Is primary breast melanoma a true pathological entity? The argument against it

Area of Science:

• Oncology
• Dermatology
• Pathology

Background:

• Primary melanoma of the breast parenchyma (PMBP) is a rare entity with poorly understood pathogenesis.
• Previous studies have documented cases, but a comprehensive understanding of its presentation and outcomes is lacking.
• This study reviews existing literature and presents new pathological analyses to elucidate PMBP.

Purpose of the Study:

• To review the clinical presentation and outcomes of reported primary melanoma of the breast parenchyma cases.
• To provide detailed pathological analysis of four additional cases.
• To discuss potential pathogenetic theories for this condition.

Main Methods:

• Systematic review of 29 published studies (95 patients).
• Inclusion of four new patient cases, totaling 99 patients.
• Analysis of patient demographics, previous melanoma history, tumor location, nodal status, treatment modalities, and survival data.

Main Results:

• The study identified 99 cases, predominantly in females (92%) with a median age of 50.
• A significant proportion (56%) had a history of skin melanoma, often on the trunk or extremities.
• Nodal metastases (40.3%) and distant metastatic disease (30%) were common at presentation, with a median survival of 11.5 months.

Conclusions:

• Breast parenchymal melanomas are likely metastatic lesions from known or unknown primary skin melanomas, not true PMBP.
• A multidisciplinary approach is crucial for management.
• Treatment should involve surgical excision with negative margins, lymphadenectomy for positive nodes, and neoadjuvant/adjuvant immunotherapy.