Diagnosis of malignant granular cell tumor by fine needle aspiration cytology - A case report

BACKGROUND: Malignant granular cell tumors (GCT) are the rarest of all sarc omas, and the histologic differentiation from their benign counterpart may be extremely difficult or impossible unless metastatic disease is demonstra ted. To our knowledge, this is the first report of a malignant GCT diagnose d by fine needle aspiration (FNA) cytology. CASE: A 70-year-old, Caucasian female presented with a progressively enlarg ing left supraclavicular mass. FNA of the mass revealed a metastatic tumor cytologically consistent with GCT. With this diagnosis, a search for other metastatic sites was initiated. Computed tomography (CT) scan revealed seve ral tumor nodules in the lungs and liver. CT-guided FNA and tru-cut needle biopsy of a liver mass confirmed the diagnosis of metastatic GCT. In search ing for a primary site, the patient revealed a clinical history of having h ad a tumor removed from. her back two months before; it was reported to be an atypical GCT. Comparison of the three tumors revealed similar histologic , cytologic and immunohistochemical features. CONCLUSION: Evidence of mild to moderate cytologic atypia; increased mitoti c activity; locally aggressive growth; increased proliferative activity as demonstrated by immunohistochemical evaluation of proliferation markers; an d DNA ploidy analysis, as reported for this case, may be helpful in predict ing malignant behavior of GCTs.