Benign conjunctival fibrous histiocytoma involving the medial rectus

We present the case of a woman in her 50s who attended the emergency department with a 3-week history of a rapidly growing, painless lesion in her left eye. She reported no additional symptoms and had no relevant medical, family or ocular history. On examination, a subconjunctival nodule measuring approximately 4×4 mm was noted in the nasal conjunctiva. The lesion was elevated, and no other abnormalities were observed. Extraocular movements were intact. The patient was scheduled for surgical excision. During surgery, the lesion had increased in size to 6×6 mm and was found to infiltrate the superficial sclera and the insertion of the medial rectus muscle. Histopathological analysis confirmed a diagnosis of benign fibrous histiocytoma. We detail the surgical technique employed and provide a review of the literature. To date, only one other case involving the medial rectus has been reported, which occurred in a 17-year-old girl.