Myxofibrosarcoma in the skin.

Myxofibrosarcoma, also known as myxoid malignant fibrous histiocytoma, is increasingly recognized as a distinct malignant neoplasm of fibroblastic origin with variable clinical and histopathologic features. Myxofibrosarcomas are among the most common malignant mesenchymal neoplasms of older adults, and approximately two thirds develop within the dermis or subcutis. Herein, we describe the clinicopathologic features of four cases of myxofibrosarcoma involving the skin. Three of these cases were initially misdiagnosed as benign cutaneous neoplasms, two as myxoid neurofibroma. These cases illustrate the clinicopathologic spectrum encompassed by myxofibrosarcoma in the skin and highlight the diagnostic difficulties it may present.