9th INTEGRATED SURGICAL COURSE

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9th INTEGRATED SURGICAL COURSE

• Prepared by
• Dr. Mohammed Al-Naami, FRCSC, FACS
• Associate Professor
• Consultant General Surgeon

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• Retroperitoneal fibrosis

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• Is considered idiopathic in about one-third of
  all cases
• Has been associated with hydralazine, ergotamine,
  methyldopa, and alpha-blocking agents
• Is excluded if only one ureter appears to be
  involved
• Can be treated surgically with ureteral
  transportation, renal auto-transplantation, or
  omental encasement
• Cannot be accurately diagnosed with intravenous
  pyelography
• ANSWER D

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EXPLANATION

• Retroperitoneal fibrosis is a rare condition, and
  is idiopathic in etiology in about two-thirds of
  all cases (usually called Osmonds disease). An
  association with various medications has been
  shown, which include methysergide, ergotamine,
  hydralazine, methyldopa, and beta-blocking
  agents. The key characteristic of retroperitonel
  fibrosis is its effect on the ureters which pass
  through it. Constriction leading to obstruction
  is the result of entrapment of the ureters ,
  which will vary the presentation based on
  severity of the obstructive uropathy. Intravenous
  pyelogram (IVP) usually provides an accurate
  diagnosis, with characteristic signs of medial
  displacement, hydronephrosis/hydroureter proximal
  to the lesion, and a long segment of affected
  ureter. The strictures are usually bilateral and
  symmetrical, however, only one ureter may be
  involved.

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EXPLANATIONcont

• Mild cases with low-grade obstruction can be
  treated initially with medical management. This
  involves steroids and cessation of any associated
  medications. Failure of this regimen is seen by
  the lack of improvement over several week, and
  surgical management should be considered at this
  time. High grade or severe cases of obstruction
  will require surgical management and perhaps
  immediate nephrostomy if indicated. The
  cornerstone of surgical management is liberation
  of the ureters from the retroperitoneum.
  Concomittant intraperitoneal transposition of
  the ureters may be required, and encasement with
  ometum may also be necessary. Renal
  autotransplantation should also be considered,
  given its low complication risk.

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• 2. Primary retroperitoneal tumours

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ANSWER A

• Are malignant in 60-85 of all cases
• Are classified as either mesodermal or neurologic
  in origin, the latter of which comprises the
  majority of these tumors
• Can be clearly defined with a combination of
  magnetic resonance imaging (MRI) and computed
  tomography (CT) angiography, however, shows
  limited utility in their evaluation
• Can be effectively treated with partial resection
  and chemotherapy, with a significant improvement
  in medium survival at 5 years
• Are mostly found to have low histologic grade and
  be of small (lt5cm) size at the time of diagnosis

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EXPLANATION

• Retroperitoneal tumours are challenging both in
  diagnosis and in treatment. The majority of
  retroperitoneal tumors are discovered well after
  they have involved contiguous structures and
  organs. They are a rare phenomenon with an
  incidence of 0.3-3, and are classified as either
  mesodermal or neural in origin. Overall,
  retroperitoneal tumors are malignant 60-85 of
  the time, with the majority of malignant 60-85
  of the time, with the majority of malignant
  tumours being mesodermal in origin. Diagnosis
  and determination of resectability is based on a
  combination of CT, MRI and angiography.
  Evaluation of retroperitoneal soft tissue
  sarcomas has shown that the majority are greater
  than 10 cm in size (60) and have a high-grade
  histology (64) at presentation. Most common
  presenting symptoms include a palpable abdominal
  mass, lower extremity neurologic symptoms, and
  pain.

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EXPLANATIONcont

• In terms of treatment, the primary treatment
  should be aimed at complete resection of tumor.
  Complete resection of primary disease provides a
  median survival time of 103 months, while
  incomplete and no resection provides a medium
  survival of 18 months. Analysis of median
  survival times has shown that incomplete
  resection does not provide significant increase
  in survival than chemotherapy (doxorubicin based)
  and/or radiation therapy for unresectable tumors.
  However, partial resection has been shown to
  provide some symptomatic relief, and thus should
  be reserved for cases in which partial resection
  may provide palliation. Overall high-grade
  histology, unresectability, and positive gross
  margin are the strongest factors negatively
  influencing survival for these tumours.

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• 3. According to current guidelines for the
  management of retroperitoneal hematomas

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ANSWER B

• Zone 3 hematomas due to penetrating injury in a
  stable patient should be managed non-operatively,
  with pelvic angiography to determine potential
  sites for embolization
• Exploration of non-expanding stable zone 2
  hematomas due to blunt trauma increases the
  likelihood of renal injury and/or loss of the
  kidney
• Supramesocolic zone 1 hematomas should first be
  approached by gaining control of the abdominal
  aorta via the midline posterior peritoneum at the
  supraceliac aorta
• The most common site of blunt trauma to the
  abdominal aorta is at the origin of the superior
  mesenteric artery (SMA)
• Infrarenal lacerations of the abdominal aorta are
  associated with the highest mortality rate

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EXPLANATION

• The retroperitoneum is roughly divided into three
  major anatomic zones. Zone 1 is the midline
  retroperitoneum and contains the suprarenal
  abdominal aorta, IVC, superior mesenteric and
  proximal renal arteries. A hematoma in this area
  should warrant exploration for both blunt and
  penetrating trauma, as the likelihood of major
  vessel injury is high. The transverse mesocolon
  provides the boundary between the two types of
  zone 1 hematomas. Supramesocolic hematomas
  usually arise from aortic, celiac, proximal SMA,
  or renal arterial injuries. Vascular control
  should begin with clamping of the abdominal aorta
  at the diaphragmatic hiatus and left-sided medial
  visceral rotation (Mattox maneuver).
  Inframesocolic hematomas generally arises from
  aortic or inferior vena caval injuries. Proximal
  control should be at the supraceliac aorta, with
  exposure via the posterior peritoneum in the
  midline similar to approaching an infrarenal
  aortic aneurysm.

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EXPLANATION.continue!

• Zone 2 of the retroperitoneum are the paired
  perinephric spaces, which contain the kidneys and
  renal vessels. Hematomas resulting from blunt
  trauma in zone 2 warrant exploration only if
  there is expansion or instability, as studies
  have shown an increase in subsequent loss of the
  kidney otherwise. Given the need for exploration,
  some centers advocate obtaining proximal control
  of the renal vessels at the aorta prior to
  incising Gerotas fascia. Other centers incise
  the fascia and clamp the hilum after medially
  rotating the kidney. Regardless, evaluation of
  injury along with watertight closure of the
  collecting system should remain the primary
  goals. Zone 3 is the pelvic retroperitoneum, and
  contains the iliac vessels and the ureters. Blunt
  trauma resulting in non expanding stable
  hematomas are often secondary to pelvic fracture
  or bleeding which is most likely best controlled
  by angiographic embolization and thus should not
  be explored. Blunt expanding hematomas in this
  area should be explored given the likelihood of
  iliac vessel injury.

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• 4. Rectus sheath hematomas

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ANSWER A

• Can be caused by coughing
• Are rarely associated with anticoagulative
  therapy
• Usually occur at the semicircular line of Douglas
  at the entry site of the superior epigastric
  artery into the rectus sheath
• Are infrequently palpable on physical examination
• Usually require operative drainage

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EXPLANATION

• Rectus sheath hematomas may mimic intra-abdominal
  disease, and so care should be taken with
  diagnosis to avoid an unnecessary laparotomy.
  Trauma is the primary cause of rectus sheath
  hematomas, and may be caused by various blunt
  traumas or even vigorous paroxyms of coughing.
  Other causes include collagen vascular diseases,
  and infectious disease like typhoid fever. Also
  many patients with this condition are frequently
  on anticoagulative therapy or have some type of
  blood dyscrasia. Most often, the source of
  bleeding is usually from the inferior epigastric
  vessels and not the muscle proper. Logically, it
  occurs most often at the junction of the
  semicircular line of Douglas and the rectus
  sheath where the inferior epigastric vessels
  enter the rectus sheath. Likewise, abdominal CT
  scanning or ultrasonography should adequately
  reveal a rectus sheath hematoma. Management is
  most often non-operative, although continued
  expansion of the hematoma may warrant operative
  therapy. This should usually involve simple
  evacuation, control of hemorrhage, and closure
  without drainage, Operative therapy is also
  indicated if more serious, intraabdominal
  conditions cannot be excluded in the process of
  diagnosis.

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• 5. A pneumoperitoneum of less than 20 mm Hg is
  associated with which of the following observed
  changes in the following cardiac parameters
  mean arterial pressure (MAP), systemic vascular
  resistance (SVR), and central venous pressure
  (CVP)?

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Answer A

• Increased MAP, increased SVR, increased CVP.
• Decreased MAP, decreased SVR, increased CVP.
• Increased MAP, decreased SVR, decreased CVP.
• Decreased MAP, decreased SVR, decreased CVP.
• Increased MAP, increased SVR, decreased CVP.

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Explanation

• Creation of pneumoperitoneum to an
  intraabdominal pressure of less than 20 mm Hg is
  associated in the supine position with increased
  MAP, SVR, and cardiac filling pressures. These
  effects stem from direct mechanical effects of
  the pneumoperitoneum, myocardial and vasodilatory
  effects of carbon dioxide, and sympathetic
  stimulation.

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Explanationcont
The increased cardiac filling pressures are
reflective of increased preload. CVP, pulmonary
artery wedge pressure, and pulmonary vascular
resistance, all increase secondary to increased
intrathoracic pressure transmitted via the
elevated diaphragm from the increased
intraabdominal pressure created during
pneumoperitoneum. Although the filling pressures
appear to have increased, in fact, they are
decreased. True filling pressures are determined
by calculating the difference of the
intrathoracic pressure from the observed CVP. The
increase in intrathoracic pressure is greater
than the increased in CVP will leads to decreased
filling pressures.
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Explanation.cont.

• SVR increases secondary to increased venous
  resistance, compression of the intraabdominal
  arterial tree by the pneumoperitoneum, and
  sympathetic or other chemical actions leading to
  increased after load. Increased SVR helps create
  an increased MAP.

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Explanationcont.

• In addition to these changes, cardiac output is
  decreased. Stroke volume is limited secondary to
  chemical mediators, specifically hypercarbia,
  that restrict cardiac contractility. For all
  these reasons, laparoscopic surgery with
  pneumoperitoneum is still used cautiously in the
  frail and elderly patients with limited cardiac
  or respiratory reserve.

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• 6. You are insufflating the abdomen of an
  otherwise healthy 35-year-old female for
  laparoscopic cholecystectomy when the patient
  becomes severely bradycardic. What should be your
  next course of action?

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• Continue with laparoscopic cholecystectomy
• Administer 1 mg epinephrine
• Deflate the abdomen
• Place the patient in Trendelenburg position
• Administer 10 mg procurium
• Answer C

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• 7. In sufflation of the peritoneum with CO2, has
  several effect on CO2 excretion and arterial
  CO2. Which of the following effects is correct?

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• Linearly increasing CO2 excretion linearly
  increasing PaCO2.
• Increase, then plateau of CO2, excretion
  linearly increasing PaCO2.
• Increase, then plateau of CO2 excretion
  increase, then plateau of PaCO2.
• Unchanged CO2, excretion, unchanged PaCO2
• Decreased CO2, excretion, increasing PaCO2.
• Answer B

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Explanation

• Excretion of CO2, increases as insufflation
  pressure increases from 0 to 10 mmHg, but then
  plateau with insufflation pressure greater than
  10 mmHg. CO2 excretion is proportionally related
  to absorption, and the increase and plateau in
  CO2, excretion may be caused by the initial
  increase in peritoneal surface area exposed to
  the CO2 which then stabilizes as the peritoneum
  becomes distended and has no more surface area to
  absorb additional CO2. PaCO2, however, increases
  continuously as insufflation increases from 0 to
  25 mmHg as dead space increases.

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• 8. Which of the following factors is not
  associated with postoperative nausea and
  vomiting?

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• Postoperative opioids
• Female gender
• Previous history of postoperative nausea
• History of migraine
• Smoking
• Answer E

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Explanation

• The most important predictor of postoperative
  nausea and vomiting is previous history of
  postoperative nausea. Other predictors include
  postoperative opioids, female gender, history of
  migraines, history of motion sickness, length of
  operation, and history of nonsmoking.

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• According to the National Institutes of Health
  (NIH) Consensus Development Conference Statement,
  patients interested in weight loss surgery for
  treatment of clinically severe obesity must
  satisfy several qualification for bariatric
  surgery. Which one is not qualified NIH
  recommendation?

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• Body mass index (BMI) greater than 35 kg/m2 with
  a medical co-morbidity related to morbid obesity
• BMI greater than 40 kg/m2
• Age lt18
• Poor outcomes with nonsurgical methods including
  dieting, exercise, and behavioral modifications
• Understanding of the surgical risks and
  demonstrated follow-up with previous methods of
  weight loss
• ANSWER C

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EXPLANATION

• The NIH Consensus Development Conference
  Statement summarizes the conclusions obtained
  following a 2-day conference in March 1991.
  Several basic patient criteria were recommend and
  included the following BMI gt40 kg/m2 or BMI gt35
  kg/m2 with a minimum of one medical commorbidity
  related to obesity (e.g., sleep apnea,
  Pickwickians syndrome, diabetes, mellitus, joint
  disease, gastroesophageal reflux disease, and so
  on), a demonstrated low probability to be
  successful with nonsurgical weight loss measures,
  and demonstrated ability to participate and
  maintain follow-up on a long-term basis.

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EXPLANATIONcont!

• The consensus panel was unable to agree on any
  conclusions regarding surgical weight loss
  treatment of children or adolescents, even
  subjects with BMI gt40 kg/m2. Although several
  centers perform weight loss surgery on
  adolescents, the appropriate treatment for these
  patients is not determined. Many feel the gastric
  bypass (GBP) is too radical an approach however,
  obesity during the important development stage
  adolescent may lead to significant psychologic
  sequela currently underestimated by the medical
  community. Continued study is necessary.

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• 10. Several surgical weight loss procedures have
  been performed during the development of
  bariatric surgery. Roux-en-Y gastric bypass
  procedures (GBP) is the most commonly performed
  bariatric procedure in the United States.
  Outcomes following weight loss procedures are
  frequently reported in excess body weight (EBW)
  loss. EBW is equal to the difference of a
  patients presurgical weight and his or her
  ideal body weight. How much EBW can a patient
  expect to lose at 2-years following a Roux- en-Y
  GBP?

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ANSWER C

• 15
• 31
• 65
• 86
• 100

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EXPLANATION

• The common goal for all bariatric surgical
  procedures is achieving weight loss and obtaining
  its beneficial effect on the treatment or
  prevention of obesity related medical
  comorbidities including hypertension, coronary
  artery disease, and diabetes mellitus. Roux-en-Y
  GBP, initially described by Mason and Ito, is
  currently the most commonly performed bariatric
  procedure. It uses a restrictive gastric pouch
  with a small outlet. This pouch is drained by a
  Roux intestinal limb that causes malabsorption as
  food bypasses the distal stomach , entire
  duodenum, and the proximal jejunum. Although both
  a traditional open and a laparoscopic approach
  are both available, weight loss results appear to
  be similar.

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• 11. AGB has gained significant exposure in
  Europe and Australia since the development of
  laparoscopic approach. It is becoming more
  popular in the united States, but results in the
  United States do not coincide with results seen
  abroad. Proponents emphasize the benefits of
  gastric banding compared to the time honored
  GBP. Which of the following comparisons is not
  accurate?

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• Gastric banding is more easily reversible
  compared to Roux-en-Y GBP
• Long-term weight loss (5 years) following
  successful gastric band is similar to the weight
  loss following Roux-en-Y GBP
• Mortality and gastrointestinal leak are higher
  following Roux-en-Y GBP
• AGB provides similar weight loss results as GBP
  in the super obese patient with BMI gt50 kg/m2
• Medical comorbidities improve equally well
  following gastric banding and GBP
• ANSWER D

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EXPLANATION

• Use of AGB remains controversial in the United
  States for treatment of clinically severe
  obesity. Results provided by large centers
  located in Europe and Australia demonstrate
  excellent long-term weight loss and resolution of
  medical comorbidities. However, frequent
  reoperation and lack of reproducibility in
  patient populations in the United States have
  lead to a slow acceptance for the AGB.

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EXPLANATIONcont!

• Removal of the AGB can be performed
  laparoscopically and essentially reverses many of
  the effects for AGB. In addition, long-term
  weight loss results for AGB rival those provided
  by open GBP. The literature is wanting for good
  long-term results of the laparoscopic GBP, but
  weigh gain 2-5 years following laparoscopic GBP
  is likely to mimic the open surgical procedure.
  In addition insertion of the AGB does not require
  division of the stomach or intestine. So, risk of
  gastrointestinal leak is much less following AGB.
  Mortality is much less after AGB because of its
  limited nature however, AGB appears to be most
  effective in patients with a lower BMI. Patients
  with BMI gt50 kg/m2 lose more weight following GBP
  than AGB. Other patient populations appear to
  respond differently to the band as well including
  males and Black patients.

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• 12. A 41-year-old man complains of regurgitation
  of saliva and of ingested but undigested food.
  An esophagram reveals a bird-beak deformity.
  Which of the following statements is true about
  this condition?

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Answer C

• Chest pain is common in the advanced stages of
  this disease.
• More patients are improved by forceful dilatation
  than by surgical intervention
• Manometry can be expected to show high resting
  pressures of the lower esophageal sphincter.
• Surgical treatment primarily consists of
  resection of the distal esophagus with
  reanastomosis to the stomach above the diaphgram
• Patients with this disease are at no increased
  risk for the development of carcinoma

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• 13. A 46-year-old man had a long history of
  heartburn (GERD). His x-ray showed an
  irregular, ulcerated area in the lower third of
  the esophagus. There are marked mucosal
  disruption and over hanging edges. What is the
  most likely diagnosis?

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Answer E

• Sliding hiatal hernia with GERD
• Paraesophageal hernia
• Benign esophageal stricture
• Squamous carcinoma of the esophagus
• Adenocarcinoma arising in a Barretts esophagus

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Explanation

• The history of GERD with these findings is
  highly suggestive of an adenocarcinoma arising in
  a Barretts esophagus. Squamous carcinoma is more
  likely to occur higher up in the middle third of
  the esophagus. Endoscopy and biopsy prove the
  diagnosis. The patient should be treated
  surgically by esophagectomy if carcinoma is
  confirmed.

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• 14. A 46-year-old man presents with dysphagia of
  recent onset. His esophagram shows a lesion in
  the lower third of the esophagus, which, on
  endoscopy shows 2 cm ulcer, and biopsy, proves to
  be an adenocarcinoma. His general condition is
  excellent, and his metastatic workup findings are
  negative. What should he undergo?

48
Answer D

• Chemotherapy
• Radiotherapy
• Insertion of a wide esophageal tube to improve
  swallowing
• Surgical resection of the esophagus
• A combination of chemotherapy and radiotherapy

49
Explanation

• Surgical resection of the esophagus remains the
  standard treatment for patients with carcinoma in
  the lower esophagus, provided that there is no
  known metastatic disease, and the medical
  condition allows surgical intervention. This
  offers the best palliation and hope of cure
  5-year survival rates vary between 15 and 25.
  Radiation and chemotherapy, in combination with
  surgery in selected patients, may improve these
  statistics. Management of carcinoma in the middle
  third of the esophagus may be either surgical
  resection or radiotherapy, and in the upper
  third, radiotherapy is often preferred.

50

• 15. A 33-year-old female arrives to the emergency
  department following a suspected suicide attempt
  in which she swallowed an unknown cleaning
  solution. The patient is obtunded and unable to
  provide any history. Vital signs are as follows
  temperature 38oC, BP 136/88 mmHg, HR 114 bpm, RR
  32 breaths/min. On examination, she is drooling
  from the mouth and there are visible burns in the
  oropharynx and crepitus in the neck and upper
  chest. All of the following are appropriate
  except

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• Endotracheal intubation
• Administer broad-spectrum intravenous antibiotics
• Perform endoscopy
• Administer intravenous corticosteroids
• Admit to ICU
• Answer D

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References

• Zwischenberger JB, Alpard SK, Orringer MB.
  Esophagus. In Townsend CM, Beauchamp DR, Evers
  MB, et al. (eds), Sabiston Textbook of Surgery
  The Biological Basis of Modern Surgical Practice,
  16th ed. Philadelphia, PA WB. Saunders, 2001,
  717-719.

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• 16. A 62 year-old woman is seen after a 3-day
  history of fever, abdominal pain, nausea, and
  anorexia. She has not urinated for 24h. She has
  a history of previous abdominal surgery for
  inflammatory bowel disease. Her blood pressure is
  85/64, and her pulse is 136. Her response to
  this physiologic state includes which of the
  following?

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ANSWER D

• Increase in sodium and water excretion
• Increase in renal perfusion
• Decrease in cortisol levels
• Hyperkalemia
• Hypoglycemia

55
EXPLANATION

• The biochemical changes associated with shock
  result from tissue hypoperfusion, endocrine
  response to stress, and specific organ system
  failure. During shock, the sympathetic nervous
  system and adrenal medulla are stimulated to
  release catecholamines. Renin, angiotensin,
  antidiuretic hormone, adrenocorticotropin, and
  cortisol levels increase. Resultant changes
  include sodium and water retention and an
  increase in potassium excretion, protein
  catabolism, and gluconeogenesis. Potassium levels
  rise as a result of increased tissue release,
  anaerobic metabolism, and decreased renal
  perfusion. If renal function is maintained,
  potassium excretion is high and normal plasma
  potassium levels are restored.

56

• 17. A 24-year-old woman has acute renal failure
  following postpartum hemorrhage. Laboratory
  studies showed serum glucose, 150 mg/dL sodium,
  135 mEq/L potassium, 6.5 mEq/L chloride, 105
  mEq/L and bicarbonate, 15 mEq/L. Therapy should
  include which of the following?

57
Answer C

• Decreased potassium chloride to 10 mEq/L
• Intravenous 0.9 sodium chloride
• 100 mL of 50 glucose water with 10 U insulin
• Intravenous calcitonin
• Intravenous magnesium sulfate

58
Explanation

• In hyperkalemia, all oral and intravenous
  potassium must be withheld. Sodium chloride
  worsens the metabolic acidosis. Sodium
  bicarbonate intravenously is given to divert
  potassium intracellularly by causing alkalosis.
  Calcium gluconate (1 g 10 mL of 10 solution)
  is given to counteract the effect of potassium on
  the myocardium. The hypertonic glucose solution
  stimulates the synthesis of glycogen, which
  causes cellular uptake of potassium. Small
  amounts of insulin (1U/5 g of glucose) is
  helpful. The usual recommended dose is 100 mL of
  50 glucose with 10 U of insulin. Calcitonin is
  used for treating hypercalcemia. Serum magnesium
  is also elevated in renal failure,

59

• 18. A 70-year-old woman has a small bowel fistula
  with output of 1.5 L/d. Replacement of daily
  losses should be handled using the fluid
  solution that has the following composition in
  mEq/L.

60
Answer A

• Na K Cl HCO3
• 130 4 109 28
• 154 0 154 40
• 77 0 77 0
• 167 0 0 167
• 513 0 513 0

61
Explanation

• The composition of small-intestinal fluid is
  sodium, 140 mEq/L potassium, 5 mEq/L chloride,
  104, 104 mEq/L and bicarbonate, 30 mEq/L. Daily
  losses are best replaced by administration of
  balanced salt solution (Ringers lactate) whose
  composition is depicted in A.B represents normal
  saline (0.9), C is half normal saline (0.45), D
  is M/6 sodium lactate, and E is 3 sodium
  chloride.

62

• 19. A 70-year-old man has undergone anterior
  resection for carcinoma of the rectum. He is
  extubated in the operating room (OR). In the
  recovery room, he is found to be restless with a
  heart rate of 136 bpm and a blood pressure of
  144/80 mmHg. ABG analysis on room air reveals pH,
  7.24 PCO2, 60 mmHg PO2, 54 HCO3, 25 mEq/L and
  SaO2, 90. The physiologic status can best be
  described as which of the following?

63
Answer B

• Respiratory alkalosis
• Respiratory acidosis
• Metabolic acidosis
• Metabolic alkalosis
• Combined respiratory and metabolic acidosis

64
Explanation

• Decrease in pH below 7.4 indicates acidosis.
  PCO2 is increased over 40 mmHg, suggesting
  respiratory acidosis. To differentiate pure
  from combined acidosis, pH is calculated based
  on changes in CO2. A change of 10 mmHg from 40
  mmHg changes pH by 0.08 from 7.4. In this case,
  there is a 20 mmHg increase in PCO2, which would
  decrease pH by 2 x 0.08 16 from 7.4 or 7.24.
  The measured pH is 7.24. Therefore, the patient
  has pure respiratory acidosis.

65
Explanation..cont

• Respiratory acidosis in the immediate
  postoperative period is due to inadequate
  ventilation. Adequate ventilation needs to be
  restored by prompt intubation and ventilatory
  support. Use of morphine will further depress the
  respiration.

66

• 20. A 19-year-old college student presents with a
  testicular mass, and after treatment he returns
  for regular follow-up visits. The most useful
  serum marker for detecting recurrent disease
  after treatment of non-seminomatous testicular
  cancer is

67
Answer B

• Carcinoembryonic antigen (CEA).
• ?-fetoprotein (AFP)
• Prostate-specific antigen (PSA)
• CA125
• p53-oncogene

68
Explanation

• In following patients with nonseminomatous
  testicular tumors, elevated serum levels of the ß
  subunit of human chorionic gonadotropin (hCG),
  ?-fetoprotein, and lactic dehydrogenase have been
  found to be useful indicators of tumor activity
  or recurrence. The discovery of prostate-specific
  antigen has recently been touted as a major
  breakthrough in screening for prostate cancer,
  though some clinicians feel that early diagnosis
  may have no impact on survival in this disease.
  CA125 has been used to follow ovarian cancers, it
  is fairly nonspecific but can alert the physician
  to the need for more aggressive search for
  persistent disease when relative increases are
  noted in a patient after therapy. The p53
  oncogenes have been found in soft tissue
  sarcomas, osteogenic sarcomas, and colon cancers.
  Their significance is unknown.

69

• 21. A 49-year-old woman undergoes surgical
  resection of a malignancy. The family asks about
  the prognosis. The histopathology is available
  for review. For which of the following
  malignancies does histologic grade best correlate
  with prognosis?

70
Answer E

• Lung cancer
• Melanoma
• Colonic adenocarcinoma
• Hepatocellular carcinoma
• Soft tissue sarcoma

71
EXPLANATION

• The management of malignant tumors may be guided
  by knowledge obtained by grading and staging the
  tumors. Histologic grading reflects the degree of
  anaplasia of tumor cells. Tumors in which
  histologic grading seems to have prognostic value
  include soft tissue sarcoma, transitional cell
  cancers of the bladder, astrocytoma, and
  chondrosarcoma. Grading has been of little
  predictive value in melanoma, hepatocellular
  carcinoma, or osteosarcoma. Staging is based on
  the extent of spread rather than histologic
  appearance and is more relevant in predicting the
  course of lung and colorectal cancers.

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• 22. A 37-year-old woman has developed a 6-cm mass
  on her anterior thigh over the past 10 months.
  The mass appears to be fixed to the underlying
  muscle but the overlying skin is movable. The
  most appropriate next step in management is

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• Above knee amputation
• Excisional biopsy
• Incisional biopsy
• Bone scan
• Abdominal CT scan
• ANSWER C

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EXPLANATION

• Benign soft tissue tumors far outnumber their
  malignant counterparts. Because of this,
  prolonged delays are common before definitive
  treatment of soft tissue sarcomas is instituted.
  Risk of malignancy is increased for tumors
  greater than 5 cm in largest diameter, as well as
  for those lesions that are symptomatic or that
  have enlarged rapidly over a short period of
  time. Properly performed biopsy is critical in
  the initial treatment of any soft tissue mass.
  Improperly performed biopsies can complicate the
  care of the sarcoma patient, and in rare
  circumstances even eliminate certain surgical
  options. Excisional biopsies should be reserved
  for small masses for which complete excision
  would not jeopardize subsequent treatment should
  be performed. The incision should be placed
  directly over the mass and should be oriented
  along the long axis of the extremity.

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• 23. A 50-year-old man is incidentally discovered
  to have non-Hodgkins lymphoma confined to the
  submucosa of the stomach during
  esophagogastro-duodenoscopy for dyspepsia. Which
  of the following statements is true regarding
  this condition?

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• Surgery alone cannot be considered adequate
  treatment .
• Combined chemotherapy and radiation therapy,
  without prior resection, are not effective.
• Combined chemotherapy and radiation therapy,
  without prior resection, result in a high risk
  severe hemorrhage and perforation.
• Outcome (freedom from progression and overall
  survival) is related to the histologic grade of
  the tumor
• The stomach is the most common site for
  non-Hodgkins lymphoma of the gastrointestinal
  tract.
• ANSWER E

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EXPLANATION

• The stomach is the most common site in the
  gastrointestinal tract for non-Hodgkins
  lymphoma, followed by the small intestine and the
  colon. Lymphomas constitute 3 of all malignant
  gastric tumors. Ninety percent of these lymphomas
  are of the non-Hodgkins type. Surgery alone can
  be considered adequate treatment for patients
  with non-Hodgkins lymphoma that does not
  infiltrate beyond the submucosa. However, gastric
  resection is not considered mandatory, and there
  no substantial differences in response to
  therapy, and survival when resection is compared
  with combined chemotherapy and radiation therapy,
  have been shown to be effective even in
  unresected bulky cases, and provide minimal risk
  of hemorrhage and perforation even this setting.

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• 24. A patient with a hematologic malignancy
  seeks your advice. She has read on the commercial
  Internet that treatment with interferon might be
  helpful. Interferons are correctly characterized
  by which of the following statements?

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• They are a group of complex phospholipids
• They are produced by virus-infected cells
• They enhance viral replication
• They cause Burkitts lymphoma cell lines to
  divide
• They have not been effective in the treatment of
  hairy cell leukemias.
• ANSWER B

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EXPLANATION

• The interferons are a group of glycoproteins
  first found as products of virus-infected cells
  that inhibited viral replication. Subsequently,
  they have been shown to have a variety of effects
  both on cells of the immune system and on
  malignant cells. Interferons cause Burkitts
  lymphoma cell lines to differentiate and lose the
  capacity to divide. Hematologic malignancies are
  very responsive to interferons up to 100 of
  hairy cell leukemias show some degree of
  remission. Interferon ? has been used in the
  treatment of chronic active hepatitis B and C
  with promising results in recent clinical trials.

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• 25. A 33-year-old woman seeks assistance because
  of a swelling of her right parotid gland. Biopsy
  is performed and reveals acinar carcinoma. In
  your discussion regarding surgery, which of the
  following statements regarding malignant parotid
  tumors is correct?

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ANSWER D

• Acinar carcinoma is a highly aggressive malignant
  tumor of the parotid gland.
• Squamous carcinoma of the parotid gland exhibits
  only moderately malignant behavior.
• Regional node dissection for occult metastases is
  not indicated for malignant parotid tumors
  because of their low incidence and the morbidity
  of lymphadenectomy.
• Facial nerve preservation should be attempted
  when the surgical margins of resection are free
  of tumor.
• Total parotidectomy (superficial and deep
  portions of the gland) is indicated for malignant
  tumors.

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EXPLANATION

• Acinar, adenoid cystic, and low grades of
  muco-epidermoid carcinomas exhibit moderately
  malignant behavior. Undifferentiated, squamous,
  and high grades of muco-epidermoid carcinomas are
  considered highly malignant tumors. Regional node
  dissection is indicated for malignant tumors
  because of the high (up to 50) incidence of
  occult regional metastases. Facial nerve
  preservation should be attempted when the margins
  are adequate and the tumor is well localized. The
  minimal appropriate procedure for parotid
  carcinoma is a superficial parotidectomy with
  nerve preservation. The nerve must be partially
  or totally sacrificed if the tumor directly
  involves the nerve trunk or its branches.