Br J Ophthalmol 1998;82:1433-1437 ( December )
DNA ploidy pattern in choroidal melanoma: correlation with
survival. A flow cytometry study on archival material
Paolo Toti,a
Giuseppe Greco,b
Paola Mangiavacchi,a
Alessandra Bruni,a
Marie Louise Desirèe Palmeri,a
Pietro Luzia
a Institute of Pathological Anatomy and Histology,
University of Siena, Siena, Italy, b Department of Ophthalmology and Neurosurgery, University of
Siena, Siena, Italy
Correspondence to: Professor Pietro Luzi, Institute of Pathological Anatomy and
Histology, University of Siena, Via delle Scotte, 53100 Siena, Italy.
Accepted for publication 15 April 1998
BACKGROUND/AIMS
Paraffin embedded samples have
provided an important source of material for retrospective
cytofluorimetric studies, useful in establishing the predictive value
of DNA content measurements. The aim of this study was to investigate
the incidence and type of aneuploidy in choroidal malignant melanomas
(CMM) and the significance in the clinical outcome (median follow up 55 months).
METHODSDNA content was quantified by flow
cytometry in 61 CMM from archival material. Non-tumour ocular tissue
was used as the reference diploid standard. Cases in which the
coefficient of variation (CV) of the diploid peak was >8% were
excluded. The CMM were classified as spindle A, spindle B, mixed
spindle and epithelioid, epithelioid, and necrotic.
RESULTSThe frequency of the aneuploid DNA pattern
was 38%. Necrotic tumours showed a worse clinical outcome independent
of the ploidy pattern. Spindle A tumours were found to be diploid.
Spindle B and mixed tumours showed a prevalent diploid and near diploid aneuploid pattern (DI <1.3), yet aneuploidy was not correlated with a
worse prognosis. The epithelioid tumours were prevalently diploid.
However, 83% of the aneuploid tumours were hypodiploid (DI <0.95),
and showed the worst prognosis.
CONCLUSIONThese results indicate that increasing
DNA abnormalities in CMM, especially in the epithelioid histotype, were
associated with an increasing mortality.
Keywords:
ocular melanoma;
flow cytometry;
DNA
© 1998 by British Journal of Ophthalmology
