To report a case of primary conjunctival giant cell tumor (GCT).

A 67-year-old female visited our clinic with the chief complaint of a 10-year-history of conjunctival mass in the left eye. The patient had no marked changes in the mass size, and her visual acuity and intraocular pressure were within the normal range. The protruding conjunctival mass invaded the limbal area at the 8 o’clock direction in the left eye and was 5 × 4 × 2 mm in size. Moreover, the pink-colored mass had a lobulated shape with a well-defined margin. In the adjacent mass region, concurrent presence of the conjunctival injection was observed. However, the patient did not exhibit pain or tenderness. We performed wide excision of the conjunctival mass concomitantly with amniotic membrane transplantation. Then, histopathological examinations and immunohistochemical staining of the surgical site were performed. On histopathology, the patient had findings suggestive of GCT. Additionally, immunohistochemistry was positive for CD68 and vimentin. leading to the final diagnosis of GCT.

To our knowledge, this is the first case of GCT of the conjunctiva, which has not been described in the literature. Our case highlights the importance of differential diagnosis from other protuberant conjunctival tumors. A complete removal of GCT of the conjunctiva and a recovery of aesthetic outcomes can be achieved by surgical excision of the mass.