Little-finger mass in a 29-year-old man.

Abstract

A 29-year-old male patient presented with a slowly growing mass in his left little finger. Radiologic studies showed a soft tissue mass around the middle interphalangeal joint Trucut biopsy of the mass and a subsequent resection showed a neoplasm composed of inflammatory, myxoid, and hyalinized areas. Large atypical epithelioid cells with macronucleoli and abundant cytoplasm were seen against a background of lymphocytes, plasma cells, and sheets of eosinophils. The myxoid areas showed cords of cells in a loose background alternating with areas showing lipoblast-like cells. The variegated light microscopic appearance, coupled with the cytologic features of the atypical epithelioid cells, is key to the diagnosis of myxoinflammatory fibroblastic sarcoma. This entity must be considered whenever a myxoid or inflammatory mesenchymal lesion is encountered in the distal extremities.