Immunocytochemical features of retinoblastoma in an adult
T. M. Nork, L. L. Millecchia, G. B. de Venecia, F. L. Myers and K. A. Vogel
Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison, USA. nork@eyesee.ophth.wisc.edu
OBJECTIVE: To describe the clinical course and immunocytochemical
characteristics of an unusual intraocular tumor. METHODS:
Immunocytochemical analysis of the enucleated eye with an intraocular mass
that markedly waxed and waned in size during 1 year of close observation of
a 29-year-old woman. RESULTS: Most of the tumor was composed of either
dying or rapidly proliferating cells. One area located near the retina
consisted mostly of well-differentiated cells in uniform sheets
(bacillettes) with lacelike glial processes between the tumor cells. Almost
all of the differentiated tumor cells were positive for S antigen. In
particular, the dominant cell type stained positively for both antibodies
known to be specific for those isoforms of S antigen found only in blue
cones and rods but not in red or green cones. Only a few of these cells
labeled positively with an anti-rhodopsin antibody. CONCLUSIONS: This is
the first case of adult retinoblastoma to be confirmed
immunocytochemically. The tumor was unusual because the differentiated
regions contained bacillettes composed mostly of blue cones. It is possible
that this and other adult retinoblastomas may arise from previously
existing retinocytomas.
