Incidence of skin melanoma and its clinical and histopathological characteristics in patients

Abstract

INTRODUCTION: Cutaneous melanoma is a malignant tumor, whose prevalence, incidence and mortality
depend on the characteristics of the affected population, therefore, knowing the epidemiology of our region
could improve prevention processes.
OBJECTIVE: To know the incidence of cutaneous melanoma, the clinical characteristics of the affected
population and the histological characteristics of the lesions studied.
PATHIENTS AND METHODS: Observational, retrospective and descriptive study. Patients older than 18
years of both sexes with a histopathological diagnosis of cutaneous melanoma (CM), attended at the Reina
Fabiola University Clinic (CURF) between January 2007 and December 2017, were included. Patients with
incomplete records and metastatic melanoma were excluded. Clinical variables were analyzed: sex, age,
location, family history of melanoma, and histological variables: subtype, Breslow thickness (BE), Clark
level (NC), ulceration, mitosis/mm², regression, lymphocytic infiltration (TIL), microsatellitosis,
angiolymphatic or perineural invasion. Statistical analysis: Incidence was presented as number of
cases/100,000 patients/year. Absolute and percentage frequency distributions were calculated for the
categorical variables and the mean and standard deviation statistical measures for the quantitative variables.
RESULTS: Of 918,988 patients in the period 2007-2017, 44 cases of CM were detected, resulting in an
incidence of 4.8/100,000/year. Female predominated (59.1%). The mean age (standard deviation) was 49.5
+ 16.4 years. Males were older than the females at the time of diagnosis, with a mean age of 52.2 + 14.5 vs
47.6 + 17.5, respectively. No patient had a family history of melanoma. The most frequent location was the
lower extremity in females (42.3%) and the back in males (39%). The superficial extensive subtype
predominated (72.7%). 54.4% had BE <1 mm, 77.3% did not ulcerate, 40.9% had NC III, 40.9% had
moderate TIL, 6.8% had angiolymphatic invasion, 93.2% had more than 1 mitosis/mm2
, 25.6% had no
regression. No case showed microsatellitosis or perineural invasion.
CONCLUSION: The incidence of CM in our study was 4.8/100,000 patients/year. Females in the fifth
decade of life predominated, with CM located in the trunk, with no family history. Superficial extensive
subtype histological variables prevailed, with BE <1mm in females, without microsatellitosis, ulceration,
regression or angiovascular or perineural invasion, with NC III, moderate TIL and more than 1
mitosis/mm2
.