Cytologically Yours: Unknowns: 201311: Case 4

Clinical History

57 year old female with hypoechoic nodule on ultrasound.

Cytology

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Resident Questions

• <spoiler text="Diagnosis?">
• Medullary carcinoma. </spoiler>
• <spoiler text="What syndrome is associated with this entity?">
• MEN 2A and MEN 2B.
• 80-90% are sporadic </spoiler>
• <spoiler text="What are the immunohistochemical features?">
• Immunoreactivity with CEA, TTF1, calcitonin, chromogranin, synaptophysin.
• Negative immunoreactivity with thyroglobulin </spoiler>
• <spoiler text="What extracellular material may be associated with this neoplasm?">
• Amyloid.</spoiler>

Cytologic Features

• Variable cytology/histology
• Polygonal, spindled, plasmacytoid
• Intranuclear pseudoinclusions
• Usually uniform, but can have some pleomorphism
• There may be red cytoplasmic granules on DiffQuik and the chromatin is often salt and pepper

The normal fibrinogen level is 184 to 412 mg/dL.