BALTIMORE Several classic parameters of melanoma histology are associated with survival and thus have a role in evaluating black patients, according to a poster presented at the annual meeting of the American Society of Dermatopathology.
"The incidence of melanoma in [blacks] is approximately 20 times lower than in [whites], presumptively because of the protective effects of melanin," wrote Dr. Doru T. Alexandrescu of the melanoma center at the Washington (D.C.) Hospital Center and his colleagues.
When blacks do present with melanoma, they are more likely to have stage III or IV disease, thicker primaries, and a poor prognosis. Histologic parameters of melanoma have not previously been described in black patients, the investigators noted.
For this study, the researchers analyzed the biopsy specimens of 68 black patients with malignant melanoma, of which 34 were evaluable histologically. The average patient age was 62 years.
Classic "histological parameters in melanoma such as Breslow depth, Clark level, ulceration, number of mitoses, and neutropism confirm their value in [black] patients by associating a statistically significant influence on survival," Dr. Alexandrescu and his associates wrote.
The mean Breslow depth of the biopsy specimens was 3.28 mm, and the mean Clark level was IV.
Pagetoid spread was found in 90% of specimens. Vertical growth phase was found in 70%, ulceration in 44%, neutropism in 36%, and necrosis in 30%.
The mean number of mitoses per high-power field was 1.36. Sentinel lymph-node positivity was 38%, and the local recurrence rate was 25%.
Tumor fibrosis was rated as none (0), mild (1), moderate (2), and severe (3). Mean tumor fibrosis was 1.5. In addition, the microvascular density inside the tumor was less (0.85) than it was under the tumor (1.85), compared with the surrounding skin.