Metastatic melanoma presenting as a breast mass - role of radiologist as a clinician

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

Background

Previous studies have reported cases of primary melanoma of the breast parenchyma (PMBP), but the pathogenesis of this disease 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.

Results

We identified 29 published studies (n = 95 patients) and report four new cases (n = 99). Ninety-one (92 %) patients were female, with a median age of 50 years. Previous skin melanomas were reported by 56 % of patients, with the trunk being the most common location (32.7 %) followed by the upper extremities (20 %). The most common tumor location reported (n = 73) was the right (49 %) upper outer quadrant (56 %). The median time from skin melanoma diagnosis to the presence of a breast mass was 65 months (1-192). Nodal status at presentation was reported in n = 67 (68 %) patients. Of these, positive nodal metastases were seen in 40.3 %, while distant metastatic disease at presentation was reported in 30 % of patients. Surgery was performed in 66 %, being partial mastectomy (PM) the most common procedure in 82 %. Adjuvant therapy was described in 38 patients. The 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 should not be considered as PMBP. Management should be multidisciplinary, including surgical excision aimed at obtaining negative margins with lymphadenectomy of clinically positive nodes and neoadjuvant/adjuvant immunotherapy.

A Rare Case of Breast Metastasis from a Primary Lung Tumor: Case Report

Breast metastasis originating from a primary lung tumor is exceedingly rare and can present challenges in distinguishing it from primary breast cancer. This case report discusses the management of a 64-year-old woman who initially presented with a nodule in her left breast. A biopsy revealed an infiltrating ductal carcinoma. Despite negative BRCA genetic testing, her significant family history of cancer and the presence of a newly detected right breast lesion led to a bilateral mastectomy. Post-operative imaging identified multiple hypodense nodules and a spiculated pulmonary nodule, necessitating further investigation. An endoscopic lung biopsy confirmed a primary pulmonary carcinoma with histological features similar to the breast carcinoma, suggesting the lung as the primary source. This case highlights the complexity of differentiating breast metastasis originating from a lung tumor and primary breast cancer. It underscores the importance of comprehensive diagnostic evaluations and the consideration of extramammary origins in metastatic cases. The findings emphasize the role of multidisciplinary teams in managing such rare and challenging cases and highlight the necessity for thorough and repeated assessments in atypical breast cancer presentations.

Treated Primary Cutaneous Malignant Melanoma With Later Metastasis Found in Clinical Presentation of Left Axilla Lymphadenopathy: A Case Report

This case report details the rare instance of metastatic spread of cutaneous malignant melanoma to the breast in a 50-year-old female. The patient presented with a palpable axillary mass confirmed to be metastasis despite excision and closure of the primary malignancy. The mass seen in clinical and radiological presentations presented with features of complicated differentiation from a primary breast tumor. Biopsy and staining with immunohistochemical markers S100 and Sox10 played a critical role in confirming the melanocytic origin of this metastatic lesion. Breast metastases are associated with poor prognosis, and this case emphasizes the importance of in-depth evaluations for patients with a history of malignant melanoma and the need for ongoing clinical awareness in this field.