Eleven soft tissue
clear cell sarcomas (CCS) were examined flow cytometrically for their
DNA content with a correlation of the
DNA with the patients' survival. Diploidy was expressed in six
sarcomas and it conferred a longer survival (mean, 68.6 months) than
aneuploid sarcomas (mean, 8.2 months). For comparison, 13
metastases to soft tissues from cutaneous
melanomas were assessed by flow cytometric study. The
aneuploid neoplasms of both entities were categorized into low and high degree based on extent of the
DNA index (DI). Low degree was defined by a DI of less than or equal to 1.5 and high degree by a DI of greater than 1.5. Significant differences in
DNA content between CCS and metastatic
melanomas were observed.
Melanomas were preponderantly
aneuploid (11/13) of high degree (mean DI, 1.7) whereas CCS manifested more diploidy (six of 11) and their
aneuploidy was of a low degree (mean DI, 1.2; P = 0.001).
Clear cell sarcomas and
melanomas were also examined for their immunoreactivity to
S-100 protein and HMB-45
antigen. All CCS reacted with
S-100 protein and HMB-45. In CCS the reactions were diffuse for both in six
tumors, diffuse with HMB-45 and moderate to
S-100 protein in three
tumors and diffuse with S-100 and moderate with HMB-45 in two
tumors. All
melanomas reacted diffusely to
S-100 protein except for one heavily pigmented
tumor which reacted only focally. The reaction to HMB-45 was diffuse in nine and focal in three
melanomas. These data suggest that measurements of
DNA content in CCS may be valuable in predicting clinical outcome and that there are quantitative differences in
DNA content between CCS and metastatic
melanoma in soft tissues.