Sclerosing epithelioid fibrosarcoma of the chest wall: Sclerosing epithelioid fibrosarcoma

ABSTRACT Sclerosing epithelioid fibrosarcoma is an unusual variant of fibrosarcoma composed of epithelioid cells arranged in strands and nests in the background of a highly sclerotic collagenous stroma. Despite the relatively bland appearance and low mitotic activity, the tumor is capable of local recurrence and distant metastasis. We report a case of sclerosing epithelioid fibrosarcoma arising from the chest wall in a 26‐year‐old man. Microscopically, the tumor showed proliferation of round, oval, or angulated tumor cells in the sclerotic collagenous stroma. The tumor cells were small to medium in size, had pale eosinophilic cytoplasm and were arranged in cords, strands, and clusters. Immunohistochemically, the tumor cells were diffusely positive for vimentin, but negative for pan‐cytokeratin, S100 protein, human melanoma black 45, CD34, smooth muscle actin, and desmin. The tumor cells showed paranuclear dot‐like staining for beta‐catenin on immunostaining, but no nuclear staining was observed. The patient is alive 13 months after surgery.