AMR SeriesSelected Case From the Arkadi M. Rywlin International Pathology Slide Seminar Sclerotic (Fibroma-like) Lipoma, Dorsum of Right HandAllen, Philip W. MBBS, FRCPAAuthor Information Department of Surgical Pathology, SA Pathology, Flinders Medical Centre, SA, Australia The author has no funding or conflicts of interest to disclose. Reprints: Philip W. Allen, MBBS, FRCPA, Department of Surgical Pathology, SA Pathology, Flinders Medical Centre, Bedford Park, SA 5042, Australia (e-mail: [email protected]). All figures can be viewed online in color at http://www.anatomicpathology.com. Advances In Anatomic Pathology: January 2013 - Volume 20 - Issue 1 - p 68-72 doi: 10.1097/PAP.0b013e31827b65e3 Buy Metrics Abstract Approximately 26 sclerotic lipomas have been reported since Zelger and colleagues’ 1997 report of 5 cases involving the scalp and hands. In 2006, Laskin and colleagues published 21 sclerotic lipomas in a study restricted to tumors of the hands and feet. Patients’ ages ranged from 7 to 72 years (mean and median 39 y); there were 12 males and 9 females; the masses, which were mostly asymptomatic and solitary, ranged from 0.6 to 2.2 cm (median 1.2 cm, mean 1.3 cm) and involved fingers (N=17), hands or wrists (N=3), and toes (N=1). Microscopically, lesions were well circumscribed, of low cellularity, and consisted of cytologically bland spindle and stellate-shaped cells with a minor component of randomly dispersed adipocytes embedded in a collagenous to myxocollagenous stroma. Eight tumors were fibroma-like with dense fibrosclerotic stroma and inconspicuous blood vessels. One tumor exhibited features of spindle cell/pleomorphic lipoma, whereas another displayed a vague onion skin–like arrangement of collagen reminiscent of a sclerotic (storiform) fibroma. The mitotic activity was negligible. Nonlipogenic cells were immunoreactive for CD99 (6/6) CD34 (6/8), S100 (4/7), and smooth muscle actin (2/6). Follow-up on 8 patients (range, 1 to 20 y, median 9.5 y) revealed no recurrence in 6 and possible persistent tumor in 2 after simple excision. The slide circulated to club members was from a 35-mm tumor on the dorsum of the right hand of a male aged 75. Club members generally agreed with a diagnosis of sclerotic lipoma but opinions differed as to whether it is a specific entity or a variant of spindle cell lipoma or dendritic fibromyxolipoma. © 2013 Lippincott Williams & Wilkins, Inc.