The association between melanoma, lymphoma, and other primary neoplasms.

BACKGROUND AND OBJECTIVE: Reports of multiple primary tumors are not new. However, we have noted a disproportionate number of patients with melanoma in whom lymphoma develops and wanted to define the incidence of this association. DESIGN: All 664 patients with melanoma treated at Yale-New Haven Hospital, Conn, during the 5-year period from 1986 to 1991 were reviewed. The incidence of all the associated malignant neoplasms among our patients with melanoma was compared with the incidence that would be expected in the normal population adjusted for age, race, and sex. RESULTS: Among the 664 patients, 54 (8.1%) had one or more additional malignant neoplasms. Of the 10 different malignant tumor types recorded, lymphomas were the most prevalent. This incidence of lymphoma among the melanoma patients was 12 of 664, resulting in an incidence of 548 per 100,000 population, 16 times higher (P < .0125) than the expected incidence (34 per 100,000) when adjusted for age, sex, and race. CONCLUSIONS: The incidence of a second malignant neoplasm in our patients with melanoma was 8.1%. Lymphoma was a particularly common type of second malignancy, showing an incidence more than 16-fold higher than that expected in the normal population. It is particularly important, from a clinical point of view, to be aware of this when clinically palpable lymph nodes develop in areas not normally the site of regional lymphatic drainage of the primary melanoma.