Subconjunctival Herniated Orbital Fat Mimicking Adipocytic Neoplasm

To describe and discuss rare and benign conditions of subconjunctival orbital fat herniation that may mimic adipocytic neoplasm.

Sixteen eyes of 13 patients with subconjunctival orbital fat herniation were included. They all underwent transconjunctival excision owing to cosmesis, discomfort, or suspicion of malignancy. Histopathologic examination, postoperative complications, and recurrent conditions were analyzed.

Eleven male and two female patients were included. The lesion was unilateral in 10 and bilateral in 3 cases. Excision was performed via conjunctival wound and removing the prolapsed orbital fat. The conjunctiva was then closed with two to three interrupted sutures. All the histopathologic specimens revealed Lochkern cells, floret cells, and mature adipocytes separated by fibrovascular septae without hyperchromatic cells, consistent with subconjunctival herniated orbital fat. All the patients were treated successfully with transconjunctival excision without recurrence at an average follow-up of 10.6 months (range, 6 to 16 months).

Prolapse of subconjunctival orbital fat is an uncommon entity of intraorbital masses and may mimic adipocytic neoplasm. It is usually associated with a dehiscence in the Tenon capsule. Surgical excision is indicated and pathologic evaluation is necessary if any malignancy is suspected.