A. R. Narvaez Rojas1, S. Linhares5, S. Sedighim3, K. D. Klingbeil4, C. Milikowski7, G. W. Elgart8, N. Jaimes8, L. Feun6, J. R. Lutzky6, E. Avisar1, M. G. Moller2 4University Of California – Los Angeles, Department Of Surgery, Los Angeles, CA, USA 5Yale University School Of Medicine, New Haven, CT, USA 6University Of Miami, Medical Oncology, Miami, FL, USA 7University Of Miami, Pathology, Miami, FL, USA 1University Of Miami, Surgical Oncology, Miami, FL, USA 2University Of Chicago, Surgical Oncology, Chicago, IL, USA 3University Of California – Irvine, Department Of Surgery, Orange, CA, USA 8University Of Miami, Dermatology, Miami, FL, USA
Introduction:
Previous studies have reported cases of Primary Melanoma of the Breast Parenchyma (PMBP), but the pathogenesis of this condition remains poorly understood. We review the presentation and outcomes of reported cases and provide detailed pathological analysis of four additional cases. Furthermore, we discuss potential theories regarding the pathogenesis of this clinical presentation.
Methods:
A MEDLINE/Pubmed search from January 1956 through March 2023 using the terms: breast melanoma, primary breast melanoma, mammary melanoma, metastatic mammary melanoma, primary melanoma of breast parenchyma, in-transit breast/mammary melanoma metastases, and metastatic melanoma to the breast was conducted. We reviewed all papers generated in the search focusing on demographics, clinical presentation, and histopathological features. Melanomas originating from the skin on the breast were excluded. For the case illustration, each patient chart was reviewed thoroughly, including history, imaging, clinical findings, pathology reports, tumor markers, treatment, and discussions held on the tumor board
Results:
Ninety-one (92%) of patients were female, median age of 50 years-old. Fifty-six percent of patients reported previous skin melanomas, with the trunk being the most common location (32.7%) followed by upper extremities (20%). Most common reported (n=73) tumor location was the right (49%) upper outer quadrant (56%). Median time from skin melanoma diagnosis to the presence of a breast mass was 65 (1-192) months. Nodal status at presentation was reported in n=67 (68%) patients. Of those positive nodal metastases were seen in 40.3%, while distant metastatic disease at presentation was reported in 30% of patients. Surgery was reported as performed in 66% of patients, being partial mastectomy the most common procedure in 82 % patients. Adjuvant therapy was described in 38 patients. Reported (n=12) median survival was 11.5 (1-70) months.
Conclusion:
Melanomas identified in the breast parenchyma are likely the result of nodal or hematogenous spread from previously known or unknown melanomas, and it should not be considered as PMBP. Management should be multidisciplinary and surgical excision aimed to obtain negative margins with lymphadenectomy of clinically positive nodes along with neoadjuvant/adjuvant immunotherapy