Cytogenetic profile of locally invasive posterior uveal melanoma

Abstract

Purpose To analyze cytogenetic profile of locally invasive posterior uveal melanoma (UM). Methods Twenty consecutive cases of large posterior UM with histopathologically confirmed extrascleral extension were included in this non‐comparative cases series. Fine needle aspiration biopsy (FNAB) of the intraocular tumor portion was performed using 25‐gauge trans‐scleral approach, immediately after enucleation of the globe. FNAB of the extrascleral tumor portion was also performed when it was > 1mm in thickness. Sampled material underwent fluorescence in situ hybridization (FISH). Follow‐up was longer than 12 months. Results Six tumors (30%) had both intraocular and extraocular tumor samplings, whereas 14 tumors (70%) showed extrascleral extension less than 1 mm in thickness. Monosomy 3 was found in 5 tumors (25%), whereas disomy 3 in 15 tumors (75%). Cytogenetic profile of the intraocular tumor portion appears to be maintained in the extrascleral extension in all cases (100%). Five patients (25%) developed metastatic disease during follow‐up (all had monosomy 3 tumors). Conclusion Extrascleral extension appears more frequent in disomy 3 tumors. Cytogenetic profile of locally invasive posterior UM is maintained in the extrascleral tumor portion and must be considered the most important prognostic factor in locally invasive tumors.