You answered: Hepatocellular carcinoma, clear cell variant

                             CORRECT!!

CYTOPATHOLOGY:

• The smears contain a monomorphous population of polygonal cells with prominent nucleoli and clear cytoplasm arranged in broad trabeculae.
• Histochemical stain (PAS plus diastase) confirms cytoplasmic glycogen.
• Immunohistochemical stains for epithelial antigens (CAM 5.2, AE1/AE3) are positive. Polyclonal CEA reveals a canalicular stain pattern. AFP is negative.
• The cytologic features and special stains are consistent with hepatocellular carcinoma, and suggest the clear cell variant.

DISCUSSION:

• The two major types of primary carcinoma of the liver are hepatocellular carcinoma and cholangiocarcinoma (arising from bile duct epithelium). Hepatocellular carcinoma accounts for more than 90% of all primary liver carcinomas. The clear cell variant is rare (approximately 5-10% of cases are of the clear cell variety and are usually mixed with classic HCC cells)
• Fine needle aspirates usually show malignant polygonal cells with central nuclei and abundant clear to finely vacuolated cytoplasm.
• Cells are arranged in cohesive clusters or occur singly.
• Cytoplasmic glycogen gives cells the 'clear' look. Fat may also be present.
• A canalicular staining pattern with polyclonal CEA is useful is helpful in distinguishing primary clear cell HCC from other clear cell malignancies.
• Glycogen or fat in the cytoplasm pushes keratin filaments to the periphery of the cell, as identified with the peripheral cytokeratin (AE1/AE3) staining.
• A number of clear cell tumours may arise from other organs. Most are uncommon except renal cell carcinoma. The importance of clinical history cannot be overemphasised.
• Important features of metastatic adenocarcinoma are columnar cells with eccentric nuclei, evidence of acinar formation or mucin production.
• Cholangiocarcinomas typically demonstrate glandular or papillary growths pattern and are negative for glycogen and fat stains.

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REFERENCES:

DeMay RM. The Art & Science of Cytopathology. Chicago: ASCP Press, 1996.