Cristiana Iacuzzo - Breast Unit, Department of General Surgery IV, San Gerardo Hospital, Monza, Italy
Cristina Pellitteri - Breast Unit, Department of General Surgery IV, San Gerardo Hospital, Monza, Italy
Camillo Di Bella - Department of Pathology, San Gerardo Hospital, Monza, Italy
Anna Abate - Department of Diagnostic Radiology, San Gerardo Hospital, Monza, Italy

Background: The carcinoma of ectopic breast tissue represents a rare condition. The ectopic glandular tissue is frequently located in the axilla, so ectopic breast lesions must be distinguished from other subcutaneous masses arising in this location. Case presentation: We describe the case of a ۷۵-year-old woman presented to our department for the recent manifestation of an axillary cutaneous lesion. She underwent mammogram, breast ultrasound, fine-needle aspiration cytology, breast magnetic resonance imaging, thoraco-abdominal computed-tomography scan and punch biopsy, and was subsequently treated as a carcinoma of unknown primary syndrome case. The final pathologic report showed the evidence of an ectopic breast tissue cancer. Conclusion: Despite the rarity of this condition, physicians should always keep in mind the possibility of ectopic breast cancer in order to make an early diagnosis and adequately treat these patients.

Breast Cancer, Ectopic Breast, Axillary ectopic breast cancer, CUP-Syndrome