Malignant melanoma in Nigeria-pathological studies

Area of Science:

• Dermatopathology
• Oncology
• Epidemiology

Background:

• Malignant melanoma incidence and characteristics vary globally.
• Understanding melanoma presentation in specific populations is crucial for diagnosis and treatment.
• Previous hypotheses suggested pigmented skin offers resistance to melanoma.

Purpose of the Study:

• To present the pathological features of malignant melanoma cases in Nigeria.
• To analyze the demographic and clinical characteristics of melanoma in this population.
• To evaluate the origin of melanoma in relation to pre-existing moles.

Main Methods:

• Retrospective analysis of 21 histopathologically confirmed malignant melanoma cases.
• Data collected from January 1974 to December 1975 at University of Nigeria Teaching Hospital, Enugu.
• Review of patient demographics, tumor location, histological type, and clinical presentation.

Main Results:

• Malignant melanoma represented 2.4% of all tumors and 4.5% of malignant tumors.
• Peak incidence occurred in the fifth to seventh decades, with a 2:1 male to female ratio.
• Nodular melanoma was the most common type (73.2%), and 81% of cases were located on the sole of the feet.
• Melanoma appeared to originate from epidermal melanocytes, not pre-existing nevi.

Conclusions:

• Melanoma in Nigerians predominantly affects the feet, supporting the hypothesis of relative resistance in pigmented skin.
• The findings suggest melanoma arises from epidermal melanocytes, questioning the need for prophylactic removal of plantar moles.
• Tumor behavior may be influenced by local tissue factors and host immune mechanisms.