Upper New York State Society of Cytology,Inc.

Submitted by: Sharon Leo, MS, CT(ASCP), CMIAC

University of Rochester - Strong Memorial Hospital

History

A 36 year old pregnant patient presented with chest pain, atelectasis, and a large pleural effusion. A CT scan showed a 10 x 8 x 7 cm chest wall mass pushing the heart border to the left. A fine-needle aspiration from the chest wall was submitted. A cell block was made from a needle rinse.

Cellular Findings

The fine-needle aspiration biopsy(FNAB) was moderately cellular with many large aggregates of cells. Single cells with a small amount of cytoplasm and stripped nuclei were also present in the background. The tightly packed nuclei were spindle-shaped or oval and had finely granular chromatin. Nucleoli were inconspicuous/absent. Cyanophilic myxoid material was visible in the looser aggregates of cells and can be appreciated on the stained air-dry slide pictured below. Cytoplasm was scant and palely stained. The tissue also demonstrates the tightly packed arrangement of spindle-shaped cells(herringbone pattern).

Pictures: Top:High-power and air-dry(myxoid material). Bottom: Tissue from resection.

 

Diagnosis/Discussion

Malignant tumor cells present derived from synovial sarcoma.

Comment: The malignant cells are immunoreactive for vimentin, EMA, and PGP9.5, but negative for cytokeratin, LCA, synaptophysin and CD34. RT-PCR was performed on the cell block tissue at the University of Nebraska and demonstrated a SSX2/SYT translocation. The findings support the diagnosis of synovial sarcoma.

Synovial sarcoma is a soft tissue tumor and does not involve the synovial membranes. It usually occurs in the extremities and less frequently in the head/neck area, abdominal wall, retroperitoneum, and pleura. This tumor case had only a spindle cell component present(monophasic). The biphasic type of synovial sarcoma would have both a spindle and epithelial component present. However, Kilpatrick,et.al., noted that the spindle cell component predominated in the biphasic synovial sarcoma in their series. RT-PCR technique demonstrates the translocation that results from the fusion of the SYT gene on chromosome 18 to the SSX1 or SSX2 gene on chromsome X(Aubry).

References

Kilpatrick SE, Teot LA, Stanley MW, Ward WG, Savage PD, Geisinger KR. Fine-needle aspiration biopsy of synovial sarcoma: A cytomorphologic analysis of primary, recurrent, and metastatic tumors. Am J Clin Pathol. 106: 769-775, 1996.

Aubry MC, Bridge JA, Wickert R, Tazelaar, HD. Primary monophasic synovial sarcoma of the pleura. Am J Surg Patholo. 25:776-781, 2001.