EP214 Sebaceous carcinoma of the breast: a rare presentation

Introduction/Background Sebaceous carcinoma (SC) is an extremely rare malignant epithelial tumor of the breast it is a breast carcinoma with prominent sebaceous differentiation. Only thirteen examples have been reported. Thus, the aim of this case is to highlight this rare disease and report its clinical, histological and therapeutic features. Methodology We report a case and we reviewed publications using Sciencedirect and PubMed. Results A 36-year-old woman presented with a palpable mass in the left breast. She had a family history of breast cancer. Clinically, we noticed a hard and movable mass of 10 mm in the lower outer quadrant of the left breast. There were no skin lesions or axillary lymphadenopathies. The imaging described two ill-circumscribed lesions of 11 and 9 mm in the lower outer quadrant of the left breast and classified as BI-RADS 4c. Ultrasound-guided microbiopsies demonstrated invasive ductal carinomas grade 3 SBR. She conducted a left lympectomy and sentinel axillary lymph node. The frozen section showed no lymph node metastasis and a bifocal invasive carcinoma wich were 15 mm apart ; so left mammectomy was performed. On microscopic examination, the first focus of 10 mm was a SC SBR grade III. The second one of 6 mm was an invasive ductal carcinoma. Immunohistochemichal analysis has revealed that tumor cells were positive for AE1/AE3, EMA, HER2, PR, ER and AR. Ki67 was of 70%. Then, she will receive chemotherapy and radiotherapy after a fertilty preservation consultation. Conclusion SC of the breast with positive staining for AR is more aggressive. Thus, a careful follow up is necessary. More cases are warranted to clarify the particularities of this lesion, especially its prognosis. Disclosure Nothing to disclose.