Purpose
To report on the cytological characteristics of choroidal melanoma.
Methods
All patients with clinical diagnosis of choroidal melanoma from May 2009 to July 2012 who underwent prognostication FNAB were included. In this prospective, single center study of consecutive patients, clinical and diagnostic cytological characteristics of were analyzed.
Results
A total of 141 FNAB samples of 141 patients. Fifty-three percent of the patients were male and the average age for all patients was 60 years. Transcorneal (7), transcleral (69) and transvitreal (63) approaches were used (Table 1). Of 141 samples, 129 adequate samples where obtained (91 % true positive). These included 121 samples that were positive for melanoma and 8 samples that contained atypical cells consistent with melanoma. Twelve samples were inadequate (7 unsatisfactory for interpretation, 2 negative for melanoma, and 3 non-diagnostic atypical cells). Average tumor height was 6.3mm for adequate samples and 3.3 mm for inadequate samples (p=0.0001). Median tumor height was 5 and 2.8mm for adequate and inadequate saples respectively. Sample adequacy was varied significantly (p=0.029) by FNAB approach (100% transcorneal, 97% transcleral, and 84% transvitreal). Spindle cells were observed in 98% of the samples (63% mixed and 25% spindle only) where as only epithelioid cells were observed in 2% samples). Melanin was present in 80% of samples (Table 2). Tumor nuclear grade (atypia) increased with tumor height and by tumor locations (least atypia with iris tumors).
Conclusions
Cytological features such as spindle cells and melanin which where present in 98% and 80% of samples respectively are important diagnostic features. Iris melanoma has bland fetaures as compared to ciliary and choroidal melanoma. Thinner tumors (less than 3 mm in height) are likely to yield inadequate diagnostic FNAB sample.
Keywords: 624 oncology •
491 cytology •
638 pathology: human