A rare case of syringocystadenocarcinoma papilliferum of the breast: An institutional retrospective case review and brief literature review.

Syringocystadenocarcinoma papilliferum (SCACP) is a rare cutaneous adnexal tumor thought to originate from its benign counterpart, syringocystadenoma papilliferum. These tumors are predominantly located on the head and neck with their location on the breast extraordinarily reported; mammary localization poses a great diagnostic dilemma to the practicing pathologist. Herein, we report an unusual case of an 85-year-old woman with an outside diagnosis on a core needle biopsy of metaplastic mammary carcinoma. Upon consultative review of the partial mastectomy specimen, SCACP was identified. Herein, we review SCACP and the diagnostic challenge it poses, especially when localized to the breast. Furthermore, we perform a retrospective review of institutional pathology reports and identified four additional cases of SCACP diagnosed at our institution within the last decade. Finally, we briefly review the literature of SCACP. The entity of SCACP should be well known to pathologists to avoid misdiagnosis.