Adenocarcinoma of retinal pigment epithelium arising from a juxtapapillary histoplasmosis scar.

A 66-year-old woman underwent a transocular fine-needle aspiration biopsy for an enlarging mass arising from a juxtapapillary histoplasmosis scar in the left eye. The cytologic study revealed pigmented malignant cells, suggesting that the lesion was either a malignant choroidal melanoma or an adenocarcinoma of the retinal pigment epithelium. The eye was enucleated and histopathologic studies revealed findings suggestive of an adenocarcinoma of the retinal pigment epithelium. Immunohistochemical stains were positive for cytokeratin and were negative for melanoma-specific antigen, supporting an epithelial origin of the neoplasm. It is possible that the tumor developed as a neoplastic transformation of a reactive proliferation of the retinal pigment epithelium in a histoplasmosis scar. The possible association between a chorioretinal scar and the development of a tumor of the pigment epithelium is discussed herein.