Purpose and methods: The files of the Eye Pathology Institute contain only two cases of leiomyoma of the ciliary body. The diagnoses were re-evaluated, applying modern immunostainings.
Results: The tumors were composed of interlacing fascicles of spindle-shaped cells with bright eosinophilic cytoplasm and cigar-shaped nuclei. Both tumors were well-vascularized, mostly by thin, branching capillaries. Larger vessels were also seen. In one case the tumor perforated the sclera. The tumor cells reacted with the reticulum stain and the Masson trichrome and were positive for antibodies against: smooth muscle actin (SMA), muscle specific actin (MSA), laminin and vimentin (one case).
Conclusion: Leiomyoma of the ciliary body is a rare smooth muscle cell tumor that may arise from either pericytes, ciliary - or intrascleral heterotopic muscle.