Complete Excision and Gastrosoleus Turn-Down Reconstruction for Achilles Tendon Xanthoma: A Case Report.

Introduction: Tendon xanthomas are cholesterol-rich deposits associated with disorders of lipid metabolism, most classically familial hypercholesterolemia. Although primarily a dermatological or metabolic finding, they often present to orthopedic surgeons because of functional impairment, cosmetic concerns, or diagnostic uncertainty arising from a mass-like swelling. Case Report: A 33-year-old woman presented with a 3-year history of progressive, painful swelling over both Achilles tendons, worse on the right, with difficulty walking and wearing shoes. Examination revealed firm-to-hard masses adherent to the tendons, tender on the right side, with normal ankle range of motion. Total cholesterol was elevated at 228 mg/dL (reference range, 123-200 mg/dL), with low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides within their reference ranges. Magnetic resonance imaging showed bilateral fusiform thickening of the Achilles tendons. The right-sided xanthomatous mass was excised completely, and the resulting 10-cm defect was reconstructed with a gastrosoleus turn-down flap. Histopathology confirmed tendon xanthoma. At 1-year follow-up, pain had improved (Visual Analog Scale 7-2) and the American Orthopaedic Foot and Ankle Society score had increased (52-90), with the ability to perform a single-leg heel raise and no clinical recurrence. Conclusion: Achilles tendon xanthoma, although uncommon, should be considered in the differential diagnosis of heel swelling, and a lipid profile should be obtained. Orthopedic surgeons play a key role in diagnosis and surgical treatment, while collaboration with endocrinology and metabolic specialists helps guide further evaluation and reduce cardiovascular risk.