True Cavitations in Uveal Melanoma: Apoptotic Genesis

Abstract

Purpose:: To report the histopathology of true Cavitary Melanoma and to describe the apoptotic mechanism of these cavitations.

Methods:: Three surgical cases of melanoma were included: one of the ciliary body and choroid, obtained by iridiociclectomy and two of the ciliary body obtained by enucleation. The samples were studied with hematoxylin & eosin, S-100, HMB-45, Anexine-V and electronic microscopy.

Results:: All cases showed epitheloid and fusiform cells, with different cavitary sectors, and the presences of degenerative cells. The three specimens were positive for S-100 and HMB-45. An apoptotic mechanism was found in different stages by electronic microscopy and Annexin-V inmunomarcation. All cases remained free of metastasis or local invasion within 5.5 years of median follow-up.

Conclusions:: : The cavitary melanomas are rare variants of uveal melanoma. None of the cases reported previously explain the biological and clinical importance of the cavitation process. The present cases show that the process of cavitation is mainly mediated by apoptotic mechanism, and it could be a favorable prognostic factor.

Keywords: melanoma • apoptosis/cell death • oncology