Atypical fibrolipomatous vascular proliferative lesion mimicking Orbital fat prolapse in the lower eyelid: A case report and literature review.

Orbital fat prolapse (OFP) is a common age-related condition usually diagnosed clinically and managed with excision and septal repair. However, multiple orbital pathologies can mimic OFP and cause diagnostic pitfalls. We report a rare case of fibrolipomatous vascular proliferative lesion initially misdiagnosed as lower eyelid OFP. A 61-year-old male presented with progressive left lower eyelid drooping for one month, with clinical features consistent with OFP. Intraoperatively, a firm, mobile, pale deep orbital mass was found distinct from typical adipose tissue, and complete excision was performed. Histopathology showed benign proliferation of fibrous tissue, mature adipocytes and small thin-walled vessels, without atypia or mitosis. No recurrence was observed during follow-up. This case highlights that fibrovascular orbital lesions can masquerade as simple OFP. Surgeons should maintain vigilance for atypical pathology when intraoperative findings deviate from preoperative expectations, and histopathological confirmation is essential for definitive diagnosis.