A case of myxoid plexiform fibrohistiocytic tumor

A plexiform fibrohistiocytic tumor is a low-grade malignant mesenchymal neoplasm of myofibroblastic origin, with the capacity for biphasic differentiation toward a fibroblastic or histiocyte-like morphology. We report a case of myxoid plexiform fibrohistiocytic tumor occurring on the left upper arm in a 34-year old man. The lesion was a yellowish-to-pinkish color, rounded, pedunculated tumor with a short pedicle, measuring 1×1×1.5cm. Histopathological examination revealed a multinodular biphasic proliferation of fibroblast- like and histiocyte-like cells with a few osteoclast-like giant cells. This case is notable for the rare myxoid changes. To the best of our knowledge, this is the first report of a plexiform fibrohistiocytic tumor in the Korean dermatological journals.