September 2015 Case of the Month
65 year-old man with a soft tissue mass of the right neck, status post surgical excision.
Low power view shows a somewhat hypocellular spindle cell and collagenous lesion with few interspersed adipocytes. Some cords of thick, ropey collagen are noted at the left side of the field.
Thick eosinophilic bands of collagen course haphazardly throughout the lesion.
Negative
Low power view shows a somewhat hypocellular spindle cell and collagenous lesion with few interspersed adipocytes. Some cords of thick, ropey collagen are noted at the left side of the field.
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September 2015 Case of the Month
Answer: Spindle Cell Lipoma
The excisional biopsy shows a well-circumscribed spindle cell lesion, primarily made up of three components including thick ropey collagen bundles, few scattered adipocytes, and a bland spindle cell population. The multinucleated "floret-like" cells characteristic of pleomorphic lipoma are not observed in this case. Notably, the lesion shows diffuse positivity for CD34 immunostain, and negativity for S-100, SMA, and desmin (not shown). Clinically, spindle cell lipomas typically arise between the 4th and 5th decades with a striking male predominance of roughly 10:1. The lesion most often occurs in the posterior aspect of the neck or upper back. Spindle cell lipoma is benign and excision is curative.