Patients' Characteristics, Histopathological Findings, and Tumor Stage in Different Types of Malignant Melanoma: A Retrospective Multicenter Study.

Cutaneous malignant melanoma (CMM) is currently the most fatal of skin cancers accounting for 50000 deaths annually. Five distinct melanomas are described histopathologically: superficial spreading, lentigo maligna, nodular, acral lentiginous and mucosal melanoma. The aim of this study was to investigate the characteristics of patients with various types of malignant melanoma and evaluate histopathological findings. In this retrospective study, we obtained our data from the records of 111 patients with melanoma. Biopsied specimens were collected and re-evaluated. Demographic information and histopathological findings were noted. SPSS 16 was used for analyzing data. Chi-square and one-way ANOVA was conducted for comparing categorical and numerical variables respectively. The mean age of patients was 59.33±14.68 years old. Most common melanoma type was acral lentiginous (40.5%), followed by nodular (35.1%) and mucosal (10.8%). The highest tumor thickness was viewed in nodular melanoma followed by mucosal melanoma. The highest rate of metastasis, microsatellitosis, perineural invasion and Clark level of the invasion were reported in nodular and acral lentiginous respectively. The most frequent rate of ulceration and vascular invasion was reported in mucosal melanoma. Distribution of melanoma types varies largely in different regions. Lack of classic presentations in some types necessitate specific public education about warning signs. Histopathological and pathological characteristics in melanoma can aid in better staging and management of the tumor.