Immunocytochemical features of retinoblastoma in an adult.
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.
Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison, USA. nork@eyesee.ophth.wisc.edu
T M
TM
Nork
L L
LL
Millecchia
G B
GB
de Venecia
F L
FL
Myers
K A
KA
Vogel
D000328:Adult; D000911:Antibodies, Monoclonal; D019393:Arrestin / Q000032:analysis; D015353:Eye Enucleation; D005134:Eye Neoplasms / Q000737:chemistry / Q000473:pathology*; D005260:Female; D005654:Fundus Oculi; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D010446:Peptide Fragments; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D012175:Retinoblastoma / Q000737:chemistry / Q000473:pathology*; D012243:Rhodopsin / Q000032:analysis
D000911:Antibodies, Monoclonal; D019393:Arrestin; D005904:Glial Fibrillary Acidic Protein; D010446:Peptide Fragments; D018809:Proliferating Cell Nuclear Antigen; D012243:Rhodopsin