Cellblock2c HE2c 400x85 y/o M w/ remote h/o lymphoma treated with nephrectomy, splenectomy and radiation. Now presenting with a new RLL lung mass and cystic lesions in the ribs and scapula. The specimen is a fine needle aspirate of the 7th right rib.

 What is the most likely diagnosis?

A. Diffuse large B-cell lymphoma.
B. Metastatic prostatic adenocarcinoma.
C. Melanoma.
D. Metastatic renal cell carcinoma.

Smear2c Diff Quick2c 100x
Smear2c Diff Quick2c 400x


The answer is ā€œDā€, Metastatic Renal Cell Carcinoma

RCC2c 400xRenal cell carcinoma is the most common malignant tumor of the kidney and affects men more commonly. Clear cell RCC is composed of cells with abundant cytoplasm that is clear, granular, or a mixture of both, due to the presence of lipid and glycogen. The malignant cells have a low nuclear:cytoplasmic ratio, with a round to slightly irregular, eccentrically placed nucleus. PAX 82c 400xThe size of the nucleolus depends of the grade of the tumor. Pink, fibrillary material possibly representing basement membrane is characteristic. The tumor cells have a network of delicate, thin-walled blood vessels and the aspirates are often bloody. When metastasis occurs in RCC, the most common spread is to the lungs, bones, lymph nodes, liver, adrenal glands and brain. Bone metastases from RCC are predominantly osteolytic and associated with bone destruction. In this case, the tumor cells were positive for PAX-8 and RCC antigen, and negative for TTF1.

Cibas ES, Ducatman BS. Cytology : Diagnostic Principles and Clinical Correlates. 4th ed. Philadelphia, PA: Saunders/Elsevier; 2014.

 Contributed by Frida Rosenblum, M.D.