Patient proceeded to endobronchial ultrasound guided lymph node biopsy.
MICROSCOPIC DESCRIPTION: The smears and cell block contain abundant malignant epithelial cells occurring singly and in occasional clusters, in a backgroound of blood. The cells show a pleomorphic nuclei, hypochromatic chromatin, prominent nucleoli and foamy cytoplasm. Occasional cells are showing a single hard edge mucinous vacuole. The cell block contains approximately 80% tumour cells. By immunohistochemistry the tumour cells are positive for CK7 (diffuse), CK20 (focal), GATA3 (weak) and negative for CDX2, TTF1, NAPSIN-A, p40, PSA and PAX8.
DIAGNOSIS: TBNA 4L: Non-small cell carcinoma. Comment: The primary site is not clearly identified by immunohistochemistry. The more likely primary sites are urogenital tract, pancreaticobiliary tract, and upper gastrointestinal tract. A primary lung carcinoma is not excluded.