Attributes and survival patterns of multiple primary cutaneous malignant melanoma

From a series of 1495 patients with primary cutaneous malignant melanoma (PCMM), 26 patients (1.73%) had multiple primary cutaneous malignant melanoma (MPCMM). This report describes the attributes and survival patterns in this small, but important, subgroup of patients with PCMM. Of 26 patients, 23 had two primaries, two had three primaries, and one had six primaries. Five patients had synchronous and 21 patients had metachronous MPCMM. The median interval between the occurrence of the first and subsequent PCMM in these patients was 1.93 years. The estimated 5-year survival rate from the first melanoma was 83.5%; that from the last melanoma was 53.1%. In summary, MPCMM is a distinct biologic phenomenon. A second or subsequent malignant melanoma should be treated like a primary melanoma. Cancer 67:1984-1989,1991. HE ENTITY of multiple primary malignant melano-T mas was described as early as the time of Hippocrates (5th century BC), but a fairly accurate histologic description was given by Unnal at the turn of the 20th century. Pemberton, in 1858, proposed and did wide local excision for melanoma.* Fifty years later, Handley3 described the concept of lymphatic permeation and subsequent vascular invasion. Pringle began en bloc resections in 1903, maintaining the continuity of skin surrounding the lesion with subcutaneous fat, fascia, and regional lymph nodes.3 Clark et aL4 in the 1960s, suggested the concept of radial and vertical growth phase of malignant melanoma in the skin and provided a classification according to the skin layer involved by a primary cutaneous malignant melanoma (PCMM).4 In 1970, Breslow5 postulated tumor thickness as an important prognostic factor. Many other prognostic indicators have been added since then which are helpful in the management of PCMM.6.7