Unusual lipid poor spindle cell lipoma.

Area of Science:

• Oncology
• Pathology
• Radiology

Background:

• Spindle cell lipomas (SCLs) are typically benign, slow-growing lipomatous tumors.
• SCLs commonly present as painless masses in the neck, shoulders, or back of middle-aged to elderly men.
• Minimal fat content in SCLs can complicate diagnosis, mimicking other tumors.

Observation:

• This report details an unusual case of a lipid-poor SCL located in the lower extremity.
• Initial clinical and radiographic evaluations suggested a malignant neoplasm.
• Core biopsies initially revealed benign fibrocollagenous tissue, leading to marginal excision.

Findings:

• Histopathological and immunohistochemical analysis definitively diagnosed the tumor as a spindle cell lipoma.
• The lipid-poor nature and unusual location presented diagnostic challenges.

Implications:

• Awareness of SCLs presenting in atypical locations with minimal fat is crucial for radiologists, pathologists, and surgeons.
• This knowledge can improve radiologic-pathologic concordance and diagnostic confidence.
• Early and accurate diagnosis prevents unnecessary aggressive treatments for benign conditions.