Male accessory breast cancer is extremely rare, and only a few cases have been reported in the literature. It is often misdiagnosed, and there are no specific guidelines regarding its management. The aim of this systematic review was to investigate the case reports of male accessory breast cancer (MABC) published in the recent peer-reviewed literature. Electronic databases such as PubMed, ResearchGate, Google Scholar and Scopus were searched for case reports on MABC published from 2014 to 2023. Data were extracted related to the variables, which included age of the patient, location of the affected accessory breast, clinical presentation, maximum dimension of the tumour, imaging modalities used for evaluation, pre-excision histopathology, stage, management, histopathology, immunochemistry, gene profiling and follow-up. Our results show that there were 21 cases with a mean age of 69.2 years, and the commonest presentation was a lump. Six cases (28.5%) had been misdiagnosed, and the cancers had been labelled as benign lesions. Overall, 74% of cancers were located in the axilla, and there were two cases of bilateral involvement. Wide excision of the accessory breast was the major treatment modality, followed by comprehensive treatment including chemotherapy, radiotherapy and endocrine therapy, either alone or in combination. The immunochemistry analysis of the retrieved specimen played an important role in diagnosis and treatment. Four (20%) cases developed metastasis during follow-up.