Biological behaviour of cutaneous malignant melanomas

Area of Science:

• Dermatology and Oncology
• Pathology
• Epidemiology

Background:

• Cutaneous malignant melanoma classification is crucial for understanding disease behavior.
• Established classifications include lentigo maligna melanoma (LMM), superficial spreading melanoma (SSM), and nodular melanoma (NM).
• These groups exhibit distinct growth rates, prognoses, and associations with benign nevi.

Purpose of the Study:

• To evaluate the proposed classification of acral lentiginous melanoma (ALM) as a distinct clinico-histological entity.
• To assess the epidemiological and clinical validity of separating ALM from other melanoma subtypes.

Main Methods:

• Review of existing literature and clinico-histological data on cutaneous malignant melanoma subtypes.
• Comparative analysis of histological features and biological behavior across different melanoma groups.
• Epidemiological assessment of melanoma classification validity.

Main Results:

• The classification of LMM, SSM, and NM is supported by distinct biological behaviors.
• Many melanomas in acral locations show histological features intermediate between SSM and ALM.
• Classifying ALM as a separate entity from SSM lacks clear epidemiological and clinical justification.

Conclusions:

• The distinct biological behaviors of LMM, SSM, and NM support their classification as separate entities.
• The proposed classification of acral lentiginous melanoma (ALM) as a distinct entity is questionable.
• Further research is needed to clarify the precise classification and epidemiological significance of acral melanomas.