MALIGNANT PERIPHERAL-NERVE SHEATH TUMOR - A FINE-NEEDLE ASPIRATION BIOPSY STUDY

Although the histopathologic features of malignant peripheral nerve sh eath tumors (MPNST) have been well-described, the cytologic features a re less well-characterized. We retrospectively reviewed 4 aspiration s pecimens from 3 patients with histologically-proven MPNST. The biopsy specimens were obtained from the primary tumor (1 case), a local recur rence (2 cases), and a pulmonary metastasis (1 case). The patients wer e women, age 42, 61, and 70 yr. The primary tumors arose from the left neck and elbow, and from a neurofibroma in the right medial thigh. Th e latter patient had von Recklinghausen's disease. Cardinal cytomorpho logic features included aggregates and single cells with ovoid to elon gated, and comma to serpentine shapes, as well as hyperchromatic nucle i surrounded by delicate, tapering cytoplasm. Nuclear pleomorphism ran ged from slight to marked. Multinucleated giant cells were seen in 2 c ases. In general, the degree of nuclear variability within each indivi dual case exceeded that typically observed with synovial sarcoma or fi brosarcoma. Although the cytomorphologic features may strongly suggest MPNST, clinical correlation is necessary and immunocytochemistry (i.e ., S-100 protein) may help to distinguish MPNST from other spindle-cel l sarcomas. Origin from a nerve trunk or preexisting neurofibroma, or occurrence in a patient with von Recklinghausen's disease, confirms th e diagnosis of MPNST. (C) 1997 Wiley-Liss, Inc.