2004 Texas Radiological Society UNKNOWN CASES Head

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2004 Texas Radiological SocietyUNKNOWN
CASESHead Neck

• Justin Q. Ly, MD
• Douglas P. Beall, MD
• Wilford Hall Medical Center
• San Antonio, TX

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HEAD NECK

• 42-year-old female
• chronic migraines
• noncontrast head CT performed at another
  institution was reportedly unremarkable
• family h/o intracranial aneurysms MRI/MR
  angiography of COW was performed to exclude
  aneurysm

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2004 Texas Radiological SocietyDiagnosis
forHead Neck Case

• Justin Q. Ly, MD
• Douglas P. Beall, MD
• Wilford Hall Medical Center
• San Antonio, TX

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Imaging Findings

• Heterogenous, mildly expansile clivus mass on
  T1WI
• Moderately-intense uptake on bone scan
• Ground-glass attenuation on CT

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Fibrous Dysplasia of Clivus

• DDX
• Chordoma
• Chondrosarcoma
• Plasmacystoma
• Lymphoma
• GCT
• Cavernous hemangioma
• Carcinomas (adenocystic
• or nasopharyngeal)
• Mets
• Pagets
• low T1, high T2 signal
• In this case, signal not as
• ? as you would expect to see
• w/aggressive neoplastic process

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Fibrous Dysplasia of Clivus

• 1st described by Lichtenstein 1938
• Benign, presents in 1st 2 decades
• Etiol unknown
• Marrow replaced by fibro-osseous connective
  tissue replacing mature bone with structurally
  weak, immature woven bone
• Classification
• Monostotic (long bones of extremities, ribs,
  vertebrae, craniofacial bone) 70
• Polyostotic 30
• Albrights-polyostotic, skin hyperpigmentation,
  endocrine dysfxn (hyperthryoid, preocicous
  menstruation females)

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Fibrous Dysplasia of Clivus

• Craniofacial bones commonly involved-frontal,
  sphenoid, ethmoid, maxillary, mandible
• Clivus involvement in monostic form rare
• Presentation asymptomatic, headache

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Fibrous Dysplasia of Clivus

• XR-cystic, sclerotic, mixed forms (Leeds et al)
• CT-amorphous ground glass or smudgy
  appearance, thinning of cortex
• MR
• Expansile
• Heterogeneous-homogenous, low to intermediate T1
  and low to high T2 signal
• Contrast enhancement with variable signal
• Signal reflects overall cellularity, varying
  collagen content, extent of bone trabec, cyst
  formation
• May have cystic components
• Scleroticlow T1, T2 signal
• Low signal may also be seen with fibrous tissue
• Intermediate T2 signal high metabolic activity
  (Utz et al.)

Leeds at al. Fibrous dysplasia of the skull and
its differential diagnosis. Radiology
196278570-582. Utz et al. MR appearance of
fibrous dysplasia. J Comput Assist Tomogr
198913845-851
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Fibrous Dysplasia of Clivus

• Path
• Fibrous connective tissue with trabeculae of
  immature bone w/o surrounding osteoblasts
• Termination of active phaseincreasingly ossified
• Histologic degree of activity closely corresponds
  to radiologic findings (Ameli et al)
• Disease ceases to progress or evolves slowly
  after bone maturation

Ameli NO, et al. Monostotic fibrous dysplasia of
the cranial bones. Report of fourteen cases.
Neurosurg Rev 1981471-77.
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Fibrous Dysplasia of Clivus

• Tx
• Dependent on activity level, symptoms/cranial
  nerve compromise, location in skull
• If active phasetotal excision recommended (Ameli
  et al)
• Generally good prognosis, small risk of malignant
  change
• Monostotic craniofacial lesions-0.05 malign
  transformation
• Osteosarc, fibrosarc, chondrosarc

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2004 Texas Radiological SocietyUNKNOWN CASES

• Justin Q. Ly, MD
• Douglas P. Beall, MD
• Wilford Hall Medical Center
• San Antonio, TX

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