The presence of two or more malignant tumors of different histological entities in an individual is referred to as multiple primary malignant neoplasms (MPMN). These are becoming more frequently encountered and reported in clinical practice nowadays. Majority of MPMN are diagnosed in elderly, where senility might alter the management plan. Despite the increased reporting of MPMN in the literature, only a few elaborated on the management of such cases. Also, the combination of synchronous primary appendicular and breast cancers—to our knowledge—has never been reported. Here we present the first report of an appendicular adenocarcinoma synchronously presenting along with invasive ductal carcinoma of the breast. We highlight the diagnostic essentials and the multidisciplinary management approach including surgical excision and adjuvant therapy.