Lentigo maligna melanoma has no better prognosis than other types of melanoma.

We studied 48 patients with lentigo maligna melanoma (LMM) and compared the clinical stage I patients with non-LMM melanoma patients (matched by site and thickness) to see if prognosis differed. There was no significant difference in mortality from melanoma between the two groups (P = .68) after a mean follow-up time of five years (67.5 months for LMM, 60.5 months for non-LMM). In addition, a Cox multivariate analysis of the entire matched group showed that only thickness was significantly associated with death from melanoma (P = .0007) while histology (LMM v non-LMM) did not make a significant contribution (P = .61). Our data suggest that after accounting for primary tumor thickness and site, LMM and non-LMM have the same prognosis and biologic behavior, in contrast to the widely held belief that LMM has a better prognosis than other forms of melanoma.

Rapid progression of lentigo maligna to deeply invasive lentigo maligna melanoma. Report of two cases.

Two patients had lesions of lentigo maligna that evolved into deeply invasive (level 4-5) lentigo maligna melanoma during a relatively short period (two years and four years, respectively). In both patients, the clinical impression of lentigo maligna had been difficult to confirm by histopathologic analysis until the invasive tumor had developed. Both patients were actively followed up during this period of evolution, with our intention of detecting any early changes suggestive of invasive melanoma. Since deep invasion developed despite close clinical supervision, a more aggressive approach to the treatment of lentigo maligna may be warranted.

[The primary cutaneous melanoma. Clinical aspects and histopathology, basis for prognosis]. / Das primäre Melanom der Haut. Klinik und Histopathologie, Grundlagen der Prognose.

There are 4 distinct forms of primary cutaneous melanoma: superficial spreading melanoma (SSM), lentigo maligna melanoma (LMM), acral lentiginous melanoma (ALM) and nodular melanoma (NM); they differ in case history, clinic and histology. Only nodular melanoma shows a one-phase growth pattern: intraepidermal growth only occurs in connection with dermal invasion. The prognosis of the different melanoma forms however does not depend on the melanoma type but in the first place on the depth of invasion. The location of the primary and the surgical procedure are decisive only in the second place besides further histological features. Therefore early recognition is the most important method to further increase the survival rate of primary cutaneous melanoma: by periodical precautionary clinical examination of the high risk groups and by histological examination of suspicious pigmented nevi.