Corneal myxoma associated with keratoconus and Down's syndrome

Purpose. Primary myxoma of the cornea is extremely rare. Until now, only fo ur primary corneal myxomas were reported in the literature, whereas seconda ry involvement of the cornea by conjunctival and limbal tumors is much more common. Methods. We report an additional case in a 26-year-old woman with keratoconus and Down's syndrome. Excision of the corneal mass was performed by penetrating keratoplasty. Histochemical, immunohistochemistry, and ultr astructural studies were used to obtain a definitive diagnosis. Results. Th e tumor exhibited the characteristic histologic features of myxoma. The tum or cells showed immunoreactivity for vimentin but not for S-100 protein, ep ithelial membrane antigen, CAM 5.2, HHF-35, or muscle-specific actin. Ultra structural features were fibroblast-like or stellate cells with cytoplasm c ontaining abundant, rough reticulum and dilated cisternae. No recurrence wa s observed 36 months after penetrating keratoplasty. Conclusion. This is on ly the fifth report of such an occurrence. Although the coexistence of myxo ma in Down's syndrome with keratoconus is described here for the first time , the differential diagnosis of apparently evident acute hydrops on clinica l inspection should not rule out the possibility of a corneal myxoma. Histo logic analysis should therefore be performed.