Diagnostic Cytologic Features of Uveal Melanoma

To report the cytologic characteristics of uveal melanoma.

This is a prospective, single-center study of consecutive patients.

All patients with a clinical diagnosis of uveal melanoma from May 2009 to July 2013 who underwent prognostication fine-needle aspiration biopsy (FNAB) were included.

The cytologic characteristics of uveal melanoma were analyzed for 150 consecutive patients with a clinical diagnosis of uveal melanoma who were treated at the Cleveland Clinic Cole Eye Institute between May 2009 and August 2012.

Cellular features of all cases were analyzed for cell type, presence of melanin, nuclear grade, tumor-infiltrating lymphocytes, and necrosis. Cytology was then correlated with histopathology in enucleated eyes.

A total of 150 patients were included. Seven samples of tumor resections were excluded from the study because they were studied by impression smears. A total of 143 FNAB samples of 143 patients formed the basis for analysis. Fifty-three percent of the patients were male, and the average age for all patients was 60 years. Transcorneal (n = 8), transscleral (n = 71), and transvitreal (n = 64) approaches were used. Of 143 samples, 131 were adequate. Among these, spindle cells were observed in 98% (63% mixed and 35% spindle only), whereas only epithelioid cells were observed in 2 samples. Melanin granules were observed in 80% of samples. Tumor nuclear grade (atypia) increased with tumor height and by tumor location (least atypia with iris tumors).

Cytologic features such as spindle cells and melanin granules, present in 98% and 80% of samples, respectively, are important cytologic diagnostic features. Tumor nuclear grade (atypia) increased with tumor height. Iris melanoma has bland features compared with ciliary and choroidal melanoma.