Cytology of melanotic schwannoma in a fine needle aspirate and pleural fluid. A case report.
BACKGROUND
Melanotic schwannoma (MS) is a rare pigmented neural tumor most commonly occurring in the paraspinal region and involving spinal nerve roots and sympathetic ganglia. Few case reports describe the fine needle aspiration (FNA) cytology of MS. We report an additional case and for the first time describe the cytologic findings of MS in pleural fluid.


METHODS
A 44-year-old man presented with a 9.0-cm paraspinal mass associated with multiple lung nodules. FNA cytology of the paraspinal mass showed solitary and syncytially arranged spindled cells, with prominent nucleoli and variable amounts of cytoplasmic brown pigment. In pleural fluid, prominent isolated single cells were rounded and had a signet ring cell morphology. Tumor cells in both the aspirate and pleural fluid expressed S-100 protein and HMB-45.


CONCLUSIONS
The FNA cytology findings of MS correlate well with the histologic findings. In pleural fluid, however, the cells are epithelioid, and some have a signet ring morphology, mimicking adenocarcinoma.
Jaffer
S
S
Department of Cytopathology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10021, USA.
Woodruff
J M
JM
D000328:Adult; D000951:Antigens, Neoplasm; D001707:Biopsy, Needle; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D058950:Melanoma-Specific Antigens; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism; D009442:Neurilemmoma / Q000378:metabolism / Q000473:pathology* / Q000556:secondary; D016066:Pleural Effusion, Malignant / Q000378:metabolism / Q000473:pathology*; D009418:S100 Proteins / Q000378:metabolism; D013125:Spinal Neoplasms / Q000378:metabolism / Q000473:pathology*
D000951:Antigens, Neoplasm; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D009418:S100 Proteins