Korean J Dermatol.  2025 Jan;63(1):5-10.

A Case of Pleomorphic Dermal Sarcoma of the Forearm Treated with Surgical Excision and Postoperative Radiation Therapy

• Kim TM
• Jo SJ

Abstract

Pleomorphic dermal sarcoma (PDS), previously known as malignant fibrous histiocytoma, has been reclassified as undifferentiated pleomorphic sarcoma due to advancements in histological techniques, particularly in the case of skin-originating tumors known as PDS. Differential diagnosis, crucial for its aggressive nature, relies on clinical, histological, and immunohistochemical (IHC) analyses. We report a case of a 74-year-old male with a 5-cm exophytic lesion on the left dorsal forearm, diagnosed with PDS via punch biopsy revealing spindle and pleomorphic tumor cells in a storiform pattern. IHC staining exhibited positive CD10 and CD68 expression, while CD34 and desmin was negative. Subsequent imaging revealed significant muscle involvement, leading to a planned wide excision and postoperative radiation therapy. Herein, we report a rare case of PDS that occurred in an unusual extremity, discussing it with clinical and histopathological characteristics, along with a review of the historical nomenclature changes.

Keyword

Atypical fibroxanthoma; Malignant fibrous histiocytoma; Pleomorphic dermal sarcoma; Undifferentiated pleomorphic sarcoma