CT CT Fine Needle Aspiration Cytology 3

Question 1

FNA of a soft tissue mass yields spindle cells with cigar-shaped nuclei, no necrosis, and a fascicular arrangement in a 25-year-old. Which diagnosis should be considered first?

Accepted Answer

Nodular fasciitis or benign spindle cell lesion

Answer

In a young patient, a benign lesion like nodular fasciitis is the most common cause of a rapidly growing spindle cell soft tissue mass and should be excluded before considering sarcoma.

Question 2

Which immunohistochemical marker pair is most useful to differentiate mesothelioma from adenocarcinoma on cell block material from a pleural fluid or FNA?

Accepted Answer

Calretinin/WT-1 (positive in mesothelioma) vs TTF-1/CEA (positive in adenocarcinoma)

Answer

Mesothelioma expresses mesothelial markers (calretinin, WT-1, D2-40) while adenocarcinoma expresses epithelial markers (TTF-1 for lung, CEA, MOC-31), enabling reliable differentiation.

Question 3

In FNA cytology of the liver, which cytomorphologic finding is most specific for hepatocellular carcinoma (HCC) compared to metastatic adenocarcinoma?

Accepted Answer

Intracytoplasmic bile pigment and transgressing endothelial cells (sinusoidal capillaries within tumor fragments)

Answer

HCC characteristically shows intracytoplasmic bile, bile canaliculi between cells, and thin-walled capillaries traversing tumor cell groups (endothelial wrapping), features absent in metastatic carcinoma.

Question 4

FNA of a kidney mass in a 50-year-old yields cells with abundant clear cytoplasm, small round nuclei with inconspicuous nucleoli, and rich vascularity. What is the most likely diagnosis?

Accepted Answer

Clear cell renal cell carcinoma

Answer

Clear cell RCC is characterized by cells with optically clear or finely vacuolated cytoplasm (due to glycogen/lipid), low-grade nuclei, and a prominent arborizing vasculature in aspirates.

Question 5

Which adequacy criterion applies to FNA of a cystic thyroid nodule that yields only macrophages and no follicular cells?

Accepted Answer

Satisfactory if the nodule was entirely aspirated and cyst fluid examined

Answer

A cyst that has been completely aspirated and yields only macrophage-rich fluid without follicular cells is a recognized exception to the 6-group rule and can be reported as satisfactory.

CT - Certified Cytotechnologist Practice Test

CT - Certified Cytotechnologist Practice Test

CT CT Fine Needle Aspiration Cytology 3