Simultaneous primary invasive breast carcinoma and ipsilateral cutaneous melanoma of the back: Surgical approach and considerations, a case report

INTRODUCTION AND IMPORTANCE: A patient presented with ipsilateral, synchronous primary malignancies of left upper back melanoma and left breast invasive ductal carcinoma. This complex presentation was managed with a multidisciplinary approach. CASE PRESENTATION: A 61-year-old female presented with multiple cutaneous lesions, revealed to be several foci of melanoma in situ as well as a T4b melanoma of the left upper back. On staging work up, a left breast malignancy was incidentally discovered. Genetic testing did not delineate a relevant mutation to explain the synchronous malignancies. Multidisciplinary surgical planning entailed consideration of the lymphatic drainage patterns of the lesions, with both the upper back melanoma and breast carcinoma expected to drain to the left axilla. Ultimately, simultaneous resections of both malignancies were performed as well as concomitant left sentinel lymph node biopsies utilizing dual tracer technique. CLINICAL DISCUSSION: Currently, cases of synchronous primary cutaneous melanoma and independent, ipsilateral primary breast carcinoma have not been examined, and thus surgical considerations for axillary staging in this circumstance have not been discussed. The existing literature instead explores the incidence and operative challenges of one malignancy following the other after an interval of time. CONCLUSION: This case highlights the utility of a multidisciplinary team for complex oncologic presentations and discusses a creative surgical approach to address two simultaneous primary malignancies involving the left breast and ipsilateral skin of the back. This case emphasizes an exceedingly rare presentation and serves as an important example to educate medical professionals on the innovative and team-based approach to treatment.