The enigma at hour 9, behind an iridian nevus

Abstract

In the management of melanocytic tumors of the iris, one of the diagnostic challenges is to differentiate nevus from melanoma^1-2. Clinical parameters suggestive of iris melanoma include documented growth, basal diameter greater than 3 mm, infiltrative growth pattern with extension to the anterior chamber angle, sectorial cataract, secondary glaucoma and abnormal vascularity^2-3. These are lesions that should be studied with different imaging methods, such as ultrasonic biomicroscopy (UBM)⁴.

The present biomicroscopy image corresponds to the right eye of a 71-year-old female patient being followed up for an iridian nevus. There is a pigmented, raised lesion with clear borders, located at the 9th hour of the iris, extending from the iridocorneal angle to approximately 0.5 mm from the scleral limbus. The lesion has direct contact with the corneal endothelium at the level of the angle. UBM showed a solid mass, of medium-high echogenicity and heterogeneous appearance, involving the iris, the camerular sinus and partially extending to the ciliary body at the same hour location.