Spindle cell lipoma.

Spindle cell lipoma is a specific type of lipoma that is easily mistaken for a liposarcoma. An analysis of 114 cases of this tumor from the files of the Armed Forces Institute of Pathology reveals that is occurs chiefly in male patients between 45 and 70 years of age and affects the regions of the shoulder and posterior neck almost exclusively. Microscopically, it consists of an intricate mixture of lipocytes and uniform spindle cells within a matrix of mucinous material traversed by a varying number of birefringent collagen fibers. Ultrastructural studies in one case support the fibroblastic nature of the spindle cells. Followup information obtained in 63 patients with this lesion revealed a uniformly favorable clinical course, indicating that local excision is the treatment of choice, and that there is no need or reason for radical surgical procedures.