spindle cell lipoma
Spindle cell lipoma is a benign lesion in which mature fat is replaced by collagen-forming spindle cells .
Epidemiology
Spindle cell lipoma typically present in the middle aged to elderly men between the ages of 45 and 65 years .
Clinical presentation
Spindle cell lipoma has a significant tendency to occur in the subcutaneous tissue of the posterior neck, shoulder, and back .
No explanation for the predilection for the posterior neck, although this anatomic preference has been used to support the designation of spindle cell lipoma as a distinct entity .
Pathology
Spindle cell lipomas are composed of a relatively equal ratio of fat and spindle cells, yet either component may predominate, and this variation in the ratio of fat and spindle cells is responsible for the wide spectrum of imaging features .
Histologically, bland fibroblast-like spindle cells are arranged in characteristic parallel arrays (“school of fish”) with highly variable amounts of mature adipocytes on a background of “rope-like” collagen bundles, myxoid stroma, mast cells, and blood vessels (Figure 1) .
Radiographic features
The diagnosis of spindle cell lipoma should be suggested when a middle-aged man presents with a well-defined complex fatty mass in the subcutis in the posterior neck .
MRI
Non-adipose components of SCLs were isointense to skeletal muscle on T1-weighted imaging (T1W) and of variable signal compared to fat on T2-weighted (T2W) sequences . Intense enhancement of the non-adipose component further supports this diagnosis .
Treatment
Spindle cell lipoma is a benign lesion that is cured by local excision. It has never been reported to metastasize .
History and etymology
Spindle cell lipoma subtype was first described by Enzinger and Harvey in 1975 .