Exocrine pancrease

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Ppt EXOCRINE PANCREAS
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Congenital Anomalies

• Aplasia and Hypoplasia
• Total congenital absence of pancreas (aplasia,
  agenesia) is -very rare
• associated with other severe malformations
• If aplasia, agenesia is compatible with life
  clinical symptoms- steatorrhoea, diabetes
  mellitus
• Partial aplasia of organ rather than total is
  more frequent- dorsal
• ventral
• ? hypoplasia of organ
• - aplasia of dorsal anlage is the more frequent
  form

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Annular pancreas

• - a ring or annular pancreas encircles the
  descending duodenum
• rare condition
• Males gt females
• Usually associated with other anomalies and
  trisomy chromosome 21

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Clinical presentation

• In neonates intestinal obstruction
• In adults - upper abdominal pains (chr. infl.
  affecting annulus)
• Anomalies of the duct system
• Mostly atresia and congenital obstruction of
  the main pancreatic duct at the duodenum
• Rare, usually associated with other congenital
  anomalies of pancreato-billiary systems

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I. Anomalies of the duct system

• Mostly atresia and congenital obstruction of
  the main pancreatic duct at the duodenum
• Rare, usually associated with other congenital
  anomalies of pancreato-billiary systems

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ii. Pancreas divisum

• Two embryological ducts Wirsung and Santorini
  persist ? drainage in duodenum through accessory
  papilla instead of papilla of Vater only
• Clinical implication frequent pancreatitis ,
  usually segmental, involving dorsal segment (
  inadequate drainage Santorini duct)

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Pancreatic duct drainage openings

• Major pancreatic duct may drain into common
  billiary duct (surgeons)

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3. Heterotopia pancreatic tissue

• Aberrant/ ectopic pancreas pancreatic tissue
  outside its usual location without contact with
  the normal gland
• Has its own (independent) blood supply and duct
  system
• Frequently in infants with trisomy 18

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Heterotopia pancreatic tissue

• Frequent sites stomach
• jejenum
• ileum
• Meckels diverticulum
• Other intestinal diverticula

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Heterotopia. presentation

• Clinically Rarely symptomatic but can ? -
  pyloric obstruction
• ulceration
• heamorrhage
• intestinal invagination
• pain when inflammed
• In papilla of Vater obstructive pancreatitis
• Carcinoma and islet cell- tumors reported to be
  more frequent in ectopic pancrease

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Heterotopia of spleen within pancreas

• Frequency 10 of individuals accesory spleen
  encountered
• Location of ectopic spleen - hilus spleen
• tail of pancreas
• Grossly 1cm ?
• Clinically banal, but involved in disease
  processes involving the main organ eg. lymphomas

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5. Congenital cysts

• True congenital cysts uncommon
• Retention cysts most common
• Congenital Cysts multiple associated with
  polycystic disease kidney, liver and other
  malformationsof CNS (von Hippel-Lindau disease)
• Retention cysts result from dysgenetic local
  strictures

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Regressive Changes and Atrophy

• A. Lipomatosis
• Condition in which the parenchyma is dispersed
  with adipocytes( fat tissue)
• In sever forms - organ increased in size
• false impression that there is loss of organ
  parenchyma
• Cause of condition - unkown

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lipomatosis

• Condition is associated with age (adulthood) and
  obesity
• Common in subjects with adult type diabetes
  (associated with obesity) Hormone (insulin)
  implicated

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Lipomatous atrophy

• True loss pancreatic parenchyma
• Rare condition
• Encountered in infants
• Clinically characterised by - pancreatic
  insufficiency
• bone marrow dysfunction
• skeletal abnormalities

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Lipomatous atrophy

• Lipomatous atrophy
• True loss pancreatic parenchyma
• Rare condition
• Encountered in infants
• Clinically characterised by - pancreatic
  insufficiency
• bone marrow dysfunction
• skeletal abnormalities

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Pancreas in Systemic disease

• A. Cystic fibrosis
• B.Haemachromatosis
• C. Malnutrition

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c.Inflammations

• A. Acute pancreatitis
• . Chronic pancreatitis

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i. ACUTE PANCREATITIS

• Epidemiology and etiology
• Incidence of acute pancreatitis in hospitals
  estimated to be 1
• In general population 5-11 per 100,000
  population
• Can be encountered at any age but rare in
  children
• Commonly adults affected
• Age 30-70 years mean age 55 yrs
• Male and females equally affected

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Pathogenesis (a.p)

• poorly understood
• Association factors
• - alcoholism most important cause
• billiary tract diseases gall stones,
  inflammation, alcoholism
• other factors ( mumps, coxackie virus, viral
  hepatitis)
• trauma
• toxic substances including drugs) (methyl-dopa,
  diuretics)
• congenital and acquired and inherited metabolic
  abnormalities (uremia, hyperlipidemias )
• acquired ductal abnormalities

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Pathogenesis (a.p)

• Unexplained hereditary influences and
• Abnormal immune responses may also play a role

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Pathogenesis and pathophysiology (a.p.)

• The pancreas manufactures a variety of digestive
  enzymes eg. proteases and phospholipases capable
  of tissue damage including auto digestion
• Normaly pancreatic enzymes are produced in as
  inactive proenzyme ( zymogens) activation takes
  place in duodenum
• In acute pancreatitis there is suspected
  inracellular activation of enzymes with severe
  concequencies
• Recent experiments show that bile, alcohol, or
  drugs may reduce the ductal barrier ? diffusion
  of ductal contents without zymogen activation ?
• Ductal hypertension? - diffusion rupture

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Acute Pancretitis

• Currently, two clinical forms considered, though
  difficult to distinguish the two clinical forms
• Mild Clinical form - most frequent
• Severe clinical form - less frequent
• Morphology

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severe Hemorrhagic form

• In severe Hemorrhagic form
• Gross - areas of grey-white necrotic
  softening, blue-black
• Hemorrhage, yellow-white of chalky fat necrosis
  severerity varies significantly
• saponification (free faty acids calcium) may be
  encountered
• a zone of acute inflammatory cells is present
  around the foci of pancreatic necrosis
• after few days suppuration and abscess formation
  may predominate

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CHRONIC PANCREATITIS

• Deffinition- the foci of pancreatic necrosis
  Persistent, usually progressive inflammatory
  condition characterised by
• irregular sclerosis of organ
• destruction and loss of exocrine parenchyma
• Clinical presentation - recurrent/persistent
  abdominal pains
• assymptomatic
• exocrine and endocrine functions may be impaired

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CHRONIC PANCREATITIS

• Epidemiology and aetiology
• Chronic pancreatitis - less frequent than acute
  disease
• - incidence varies considerably among countries
• more frequent in tropical countries
• age lt20 yrs, malefemale ratio 11
• incidence increases with inceasing consuption
  alcohol
• Average age 40 yrs

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Chronic pancreatitis

• In tropical countries special form encountered
  Chron. calcifying
• pancreatitis
• charact. Calcifications in pancreatic duct system
• In developed countries alcohol consumption
  implicated
• Other factors - metabolic
• manifestations of systemic diseases
• idiopathic (second most frequent)

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Chronic pancreatitis

• Pathogenesis and Pathophysiology
• Excessive alcohol consumption ? hypersecretion of
  enzymes rich in calcium (stone protein) ? protein
  plugs in duct system ? obstruction and stone
  formation ?acinar cells lose their zymogen and
  height ? ductal epithelial features ?
• Steatorrhoea lipase defficiency 90
• diabetes mellitus pathogenetic mechanism unclear
  but glucagon production impaired

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Chronic pancreatitis

• Morphology
• Early stage pancreas normal - later enlarged,
  hard. (fibrosis ductal dilatation)
• Later gland shrinks smooth, grey-white
• Main duct side branches irregularly dilated
  contained fluid clear
• Calculi various size may be encountered
  (calcifying pancreatitis
• Retention cysts pseudocysts acassionaly seen
• Histo irregular loss acini, aparrent increase
  ductules
• Preserved endocrine islands which may ? in size
  and number
• Neoformation of islets from preserved ductules

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NON-ENDOCRINE TUMORS

• Majority of benign tumors of pancreas are derived
  from non-islet cells
• Epithelial adenomas are rare
• Even rarer are benign mensenchymal tumors
• Metastatic tumors more frequent than primary
  malignant tumors
• Adenocarcinomas accout for 90 of malignant
  tumors

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Classification

• Classification attempted to reflect prognosis
• Benign Neoplasms
• Adenoma
• Papillary adenoma
• Uncommon lesion
• Men and women affected equally
• Age patients in their 60s
• Presenting symptoms - upper abdominal pains
• weight loss, diarrhoea

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Adenoma. . .

• Tumor located in main pancreatic duct
• Occasionally -multiple
• Grossly soft and friable distend and obstruct
  the ductal lumen
• Histology Resemble tubulo-villous adenoma of
  colon
• Malignancy transformation potenstial low

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ii. Cystadenoma.

• Majority pancreatic cysts are non
  non-neoplastic Congenital cysts - are rare,
  Usually associated with von Hippel-Lindau
  Disease

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iii.Serous systadenoma

• Of pancreas is rare
• Elderly women in the 7th decade most commonly
  affected
• Gross tumors 6-10 cm ?
• Cut section honney comb of multiple cysts

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iv. Mucinous cystadenoma

• iv. Mucinous cystadenoma
• these have high malignant potential usually
  equated as
• carcinomas mucinous cystadenocarcinoma
• through histological examination usually
  reveal areas with
• atypical epithelium

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v. Solid and cystic tumor

• v. Solid and cystic tumor
• Currently considered as separate entity
• has strong pridelection in females
• Females aged 10-35 yrs
• tumors shown to express estrogen and progesterone
  receptors
• Clinical features discomfort to vague abdominal
  pains
• Gross large , round, size 9-10 cm?
• Histo solid sheets of uniform large cells,
  suggests islet -cell origin
• Pseudopapillae and pseudocysts secondary to tumor
  degeneration is the halmark of this neoplsm.

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CHRONIC PANCREATITIS

• Deffinition - the foci of pancreatic necrosis
• Persistent, usually progressive inflammatory
  condition characterised by
• irregular sclerosis of organ
• destruction and loss of exocrine parenchyma
• Clinical presentation - recurrent/persistent
  abdominal pains
• assymptomatic
• exocrine and endocrine functions may be impaired

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MALIGNANT NEOPLASMS

• Carcinoma
• Incidence 9-10 cases in Western countries
• Males slightly more frequently affected
• Cancer rare before 45 yrs, 80 occur in the 6th
  decade
• Aetiology

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etiological factors

• Numerous etiological factors have been implicated
  but not proven
• i. Dietary factors , esp. dietary fats ,
  are implicated, while
• vitamins and dietary fibres are considered
  protective against pacreatic cancer
• Morphology
• 60-70 located in the head
• 15 located in the body
• 10 located in the tail

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Location of Cancers

• Cancers from the head seem to be relatively
  smaller in size
• Reason tend to be obstructive, earlier diagnosed
• Direct spread beyond pancreas
• ? retroperitoneum
• ? peritoneal cavity

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Clinical symptom and prognosis

• Prognosis poorest among all pancreatic cancers
• Survival at 5years after treatment 1-2
• Clinical symptoms vague
• Avarage interval survival from diagnosis to
  death 7.5 months
• Presenting symptoms dependent on location of
  newgrowth
• Head pain, jaundice, weight loss
• Body/tail pain predominant (invasion)
  peritoneum and stomach
• Ampula Jaundice
• Other symptoms back pain, dyspepsia, nausea.