Cytologically Yours: Unknowns: 201311: Case 4

Clinical History

57 year old female with hypoechoic nodule on ultrasound.

Cytology

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Resident Questions

• Diagnosis?

• Medullary carcinoma.

What syndrome is associated with this entity?

• MEN 2A and MEN 2B.
• 80-90% are sporadic

What are the immunohistochemical features?

• Immunoreactivity with CEA, TTF1, calcitonin, chromogranin, synaptophysin.
• Negative immunoreactivity with thyroglobulin

What extracellular material may be associated with this neoplasm?

• Amyloid.

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.