Familial Atypical Mole Syndrome Manifesting as Polypoid Melanoma: A Case Report and Review of the Japanese Literature

Abstract

A family with atypical mole syndrome which manifested as polypoid melanoma in one member is reported. A 46-year-old man presented with a polypoid tumor on his lower back, which was excised under clinical diagnosis of soft fibroma. The tumor proved to be polypoid melanoma. He was referred to our clinic, and examination revealed that he had the atypical mole syndrome phenotype. The clinicopathological screening of his first-degree relatives confirmed that his 58-year-old sister had the same phenotype. In addition to our discussion of the clinical significance of polypoid melanoma, we also attempted to elucidate the characteristics of the reported Japanese cases of melanomas with atypical moles from a survey of the literature, which revealed the following characteristics: 1) younger mean age than that of total Japanese melanoma cases, 2) sun sensitive skin, 3) unexpectedly and frequently observed familial incidence (Kraemer's D1 and D2), 4) frequent site of the melanoma on the trunk and none on the sole of the foot, and 5) high incidence of superficial spreading melanoma and nodular melanoma, and 6) no cases of acral lentiginous melanoma.

Polypoid Spitz naevus: the benign counterpart of polypoid malignant melanoma

“… 1 They described a form of melanoma that lies almost completely above the surface of the skin such that both sides of the lesion seem to rest on normal surrounding epidermis. This peculiar form of melanoma has been interpreted as the result of a pattern of growth completely restricted to the papillary dermis, which undergoes a grotesque exophytic expansion toward the surface of the skin 2–6 as a variant of nodular melanoma. Initially, this form of melanoma was felt to carry a particularly poor prognosis, 1 , 6–8 but this is not generally held to be the case now as it is well established that the prognosis for polypoid melanoma is similar to other lesions of equivalent Breslow thickness.…”