Pleural Effusion Cytology of Metastatic Sclerosing Epithelioid Fibrosarcoma.

Sclerosing epithelioid fibrosarcoma (SEF) is a rarely encountered malignant fibroblastic sarcoma with an often aggressive clinical course despite its usually bland histology. We describe a case of a metastatic SEF involving a pleural effusion and describe the cytologic features as well as the use of IHC, particularly MUC4, to support the diagnosis. SEF has only been described in one prior case report in pleural effusion cytology.