MULTIPLE SPINDLE-CELL LIPOMAS - A REPORT OF 7 FAMILIAL AND 11 NONFAMILIAL CASES

Spindle cell lipoma, a variant of a benign lipoma, usually occurs as a solitary, subcutaneous, circumscribed lesion in the posterior back, n eck, or shoulders of older men. Multiple lesions are exceedingly rare. To our knowledge, there have been no previous series reported of pati ents with multiple subcutaneous spindle cell lipomas. We examine the c linicopathologic findings of a group of patients with multiple spindle cell lipomas, including seven with a familial occurrence of this dise ase. The Soft Tissue Registry of the Armed Forces Institute of Patholo gy and the consultation files of one of the authors (S.W.W.) from the Department of Pathology at the University of Michigan were searched fo r patients with multiple spindle cell lipomas. All patients' records, clinical history, and pathology were reviewed. All patients had a mini mum of two tumors that met strict morphologic criteria for spindle cel l lipoma. Pleomorphic cells, typical of pleomorphic lipoma, were obser ved in some cases and were acceptable as part of the spectrum of spind le cell Lipomas. Associated lesions, family history, ethnic background , daily habits, and natural progression of disease were recorded and c ompared. Eighteen patients in our files met the criteria for multiple spindle cell Lipomas; 4 of the 18 patients were from the same family. Three additional patients had a family history of multiple spindle cel l lipomas. The ratio of patients with multiple spindle cell lipomas to all patients with spindle cell lipoma in the two consultation files w as 0.5 and 3%, respectively. All of the patients in our study were mal e; three had a family history of females with less severe disease (few er and smaller spindle cell lipomas); however, no material from these female patients was available for review. All but four patients presen ted in their sixth through eighth decades of Life; yet, several older patients stated that their first lesion occurred in their fifth decade . Patients had between 2 and >220 lesions, which usually commenced on the posterior neck or back, commonly followed by additional bilateral lesions on the shoulders and upper torso. The natural history of this disease revealed development of multicentric lesions over several year s, for both familial and nonfamilial cases. The tumors became more cel lular as the disease progressed, often with features of pleomorphic li poma; however, no patients developed spindle cell liposarcoma. Multipl e spindle cell lipomas are rare. The clinical presentation may mimic M adelung's disease (symmetrical lipomatosis). As mentioned above, some cases are familial. Genetic predisposition must be further examined. T here appears to be no common ethnic background, environmental exposure , medical condition, or syndrome of associated lesions with multiple s pindle cell lipomas.