Diagnosis: Fibrolipoma
The biopsy confirmed a diagnosis of fibrolipoma—a rare variant of lipoma composed of a mixture of adipocytes and thick bands of fibrous connective tissues.1 Etiology for fibrolipomas is unknown. Blunt trauma rupture of the fibrous septa that prevent fat migration may result in a proliferation of adipose tissue and thereby enlargement of fibrolipomas and other lipoma variants.2 In this case, the patient’s compression of the original papule likely served as the trauma that led to its enlargement. Malignant change has not been reported with fibrolipomas.
What you’ll see—and on whom. Fibrolipomas typically are flesh-colored, pedunculated, compressible, and relatively asymptomatic.3 They have been reported on the face, neck, back, and pubic areas, among other locations. Size is variable; they can be as small as 1 cm in diameter and as large as 10 cm in diameter.4 However, fibrolipomas can grow to be “giant” if they exceed 10 cm (or 1000 g).2
Men and women are affected equally by fibrolipomas. Prevalence does not differ by race or ethnicity.
The differential include sother lipomas and skin tags
The differential for a mass such as this one includes lipomas, acrochordons (also known as skin tags), and fibrokeratomas.
Lipomas are the most common benign soft-tissue tumors and are composed of adipocytes.5 The fibrolipoma is just one variant of lipoma; others include the myxolipoma, myolipoma, spindle cell lipoma, angiolipoma, osteolipoma, and chondrolipoma.2 Lipomas typically are subcutaneous and located over the scalp, neck, and upper trunk area but can occur anywhere on the body. They are mobile and typically well circumscribed. Lipomas have a broad base with well-demarcated swelling; fibrolipomas are usually pedunculated.
Continue to: Acrochordons ("skin tags")