Dermatofibrosarcoma protuberans association with nuchal‐type fibroma

Abstract

Dermatofibrosarcoma protuberans (DFSP) is a hypercellular, storiform, CD34-positive low-grade sarcoma with honeycomb entrapment of fat, which typically involves the trunk and extremities. Nuchal-type fibroma (NTF ) is a paucicellular, CD34-positive fibrous tumor with fat entrapment, which may occur in both nuchal and extranuchal locations and in association with Gardner syndrome. We report the association of DFSP with NTF in a 43-year-old male with no personal or family history of Gardner syndrome. The patient had a past history of a DFSP removed from his back, which recurred 2 years later and was re-excised. Additionally, the patient had a typical NTF, in the posterior neck, removed at the same time. Histopathologic examination of the recurrent back lesion demonstrated a composite lesion with typical appearances of DFSP, centrally, blending into an NTF-like appearance, peripherally. Both components expressed CD34 and CD99, and lacked elastin. A review of the microscopic slides of the patient's previously excised DFSP revealed an identical lesion with surrounding NTF-like areas. While an association between NTF and fibromatosis has recently been reported, this is to our knowledge the first report of an association between NTF and DFSP. The morphologic findings suggest that there may be a continuum between these two CD34-positive lesions that have a tendency to infiltrate adipose tissue and recur.