Syringocystadenocarcinoma papilliferum (SCACP) is a rare and aggressive malignant adnexal tumor originating from apocrine or pluripotent appendageal glands, often associated with a preceding syringocystadenoma papilliferum (SCAP) or nevus sebaceus (NS). This systematic review rigorously examines SCACP through an analysis of 78 cases documented between 1980 and 2024. The study aims to provide a comprehensive review of the clinical manifestations, diagnosis, treatment modalities, and outcomes associated with SCACP, while also reappraising its associations, particularly with NS. SCACP predominantly affects older adults, with an average age of 66.3 years and a slight male predominance, commonly presenting as ulcerated nodules or plaques on the scalp. This review highlights the aggressive nature of SCACP, evidenced by significant rates of metastasis and recurrence. Treatment is primarily surgical, with Mohs micrographic surgery offering potential benefits in terms of margin control and cosmetic outcomes. The association of SCACP with NS is critically evaluated, suggesting a complex etiopathogenesis and underscoring the importance of recognizing this association for timely diagnosis and management. Our review also briefly discusses potential pitfalls faced by clinicians in the diagnosis of SCACP. Our findings emphasize the need for standardized treatment protocols and further research into targeted therapies to improve patient outcomes in SCACP.

Malignant tumors of external auditory canal (EAC) constitute less than 0.2% of all head and neck cancers. The incidence of carcinoma of the EAC is estimated to be between one in six per million populations. Majority of cancers of EAC are squamous cell carcinomas and basal cell carcinomas. Some rare and unusual tumors do occur within the ear canal including malignant melanoma, merkel cell carcinoma, angiosarcoma, lymphoma and adnexal carcinomas like ceruminous adenocaricinoma and adenoid cystic carcinoma. Ceruminous glands tumors constitute about 5% of all external auditory canal tumors. Carcinoma of the external auditory canal is a difficult diagnosis unless the tumors presents as a fungating mass protruding from the external auditory canal. Syringocystadenocarcinoma Papilliferum (SCACP) is an extremely rare cutaneous adnexal neoplasm. Syringocystadenoma papilliferum (SCAP) is thought to be precursor of SCACP. About 50 cases of SCACP have been reported in literature all over the body. The diagnosis is difficult and excisional biopsy becomes mandatory for diagnosis and treatment. We present a case of SCACP in the external auditory canal in a middle-aged female. To the best of our knowledge and belief, this is the first case of SCACP in the external auditory canal in the English literature. This prompted us to report this case.