Nuchal fibroma. A clinicopathological study of nine cases.

Nuchal fibroma apparently was first described in the second edition of Enzinger's and Weiss's text book in 1988. We have been unable to find any other accounts of this entity. We have reviewed the clinicopathological features of nine nuchal fibromas, eight of which were referred in consultation. Eight patients were men; the ages ranged from 19 to 53 years (median, 43). Patients were first seen with solitary, unencapsulated, subcutaneous swellings in the back of the neck or dorsal region measuring from 2.5 to 8 cm in maximum dimensions (median, 3.5). Macroscopically, lesions were firm, fibrofatty masses. Histologically, there were sheets of hypocellular dense collagen with interspersed mature fat, inconspicuous, small, thin-walled vessels, and entrapped nerve fibers. The picture suggested a fibrolipoma, a lipomatosis, scar tissue, or even elastofibroma, but the small amount of elastic tissue present lacked the beaded, nodular appearance of elastofibroma. Follow-up information was available in seven cases. In follow-up times from 6 months to 19 years (median, 6 years), one tumor was reexcised 4 months after an incisional biopsy and had not recurred 19 months later. None of the others recurred. The lack of a capsule, the entrapment of nerves, and the predilection for the nuchal or dorsal regions suggest that this hypocellular, benign, fibrofatty lesion is a distinct entity and not merely a lipoma.