Smooth Muscle Hamartoma

Our patient presented due to a one-year history of a slowly growing conjunctival lesion. A large, red, non-tender lesion of the right bulbar conjunctiva was identified on examination. It did not improve after several weeks of medical management with steroids. He had no previous medical or ocular history and no other findings on clinical examination. The lesion was excised and histopathologic examination disclosed morphologically benign smooth muscle bundles that stained positively for smooth muscle actin, vimentin, and desmin, while demonstrating low mitotic activity with Ki-67 staining. These findings are consistent with a diagnosis of smooth muscle hamartoma. Smooth muscle hamartomas are benign, disorganized overgrowth of mature smooth muscle tissue in an abnormal location. While congenital smooth muscle hamartomas of the conjunctiva have been rarely reported in the literature, this is the first described case of an acquired smooth muscle hamartoma in the bulbar conjunctiva. This lesion should be considered in the differential diagnosis for adolescents with similar appearing lesions.

Presentation Date: 08/25/2022

Issue Date: 09/02/2022