Tumors of the iris arising from the sphincter and dilator muscles are rare, and most authors concerned with the subject agree with Duke-Elder's5 statement that these tumors are impossible to diagnose clinically and their pathological recognition is by no means easy. Friedenwald and associates11 and Berliner1 state that they are clinically indistinguishable from malignant melanoma, especially those which are lightly pigmented.
In 1923, Li17 found only 6 iris tumors in 154 cases of tumor of the uveal tract examined microscopically at the Massachussetts Eye and Ear Infirmary from 1900 to 1922. Two of these tumors were leiomyomas of the iris. Ferrer,9 in 1949, studied five leiomyomas from the Institute of Ophthalmology of the Presbyterian Hospital of New York. Leiomyomas constituted about 9% of the 58 iris neoplasms, or about 2% of the uveal tract neoplasms in her series. Heath,14 in 1951, collected and reviewed
ERDBRINK WL, HARBERT F. Leiomyoma of the IrisReport of a Case and Review of Literature. AMA Arch Ophthalmol. 1955;53(5):643-648. doi:10.1001/archopht.1955.00930010651004