ABPath Cytopathology 3

Question 1

In a pancreatic FNA obtained by endoscopic ultrasound, elevated cyst fluid CEA most strongly suggests which lesion?

Accepted Answer

Mucinous cystic neoplasm

Answer

High cyst fluid CEA indicates a mucinous (potentially premalignant) cystic neoplasm.

Question 2

A salivary gland FNA shows a biphasic pattern of epithelial cells and metachromatic fibrillary stroma on Diff-Quik. Which diagnosis is favored?

Accepted Answer

Pleomorphic adenoma

Answer

The magenta fibrillary myxochondroid stroma with epithelial cells is classic for pleomorphic adenoma.

Question 3

Which lung cytology feature is most characteristic of small cell carcinoma?

Accepted Answer

Nuclear molding with salt-and-pepper chromatin and scant cytoplasm

Answer

Nuclear molding, fine granular chromatin, scant cytoplasm, and apoptosis characterize small cell carcinoma.

Question 4

On CSF cytology, which finding is most concerning for leptomeningeal carcinomatosis?

Accepted Answer

Clusters of atypical epithelial cells with high N/C ratio

Answer

Malignant epithelial cell clusters in CSF indicate metastatic (leptomeningeal) spread.

Question 5

Which immunostain panel best distinguishes lung adenocarcinoma from mesothelioma in an effusion?

Accepted Answer

TTF-1 and MOC-31 positive, calretinin negative

Answer

TTF-1 and MOC-31 positivity with calretinin negativity supports pulmonary adenocarcinoma over mesothelioma.

American Board of Pathology (ABPath) Practice Test