RT Journal Article SR Electronic T1 2022-RA-1612-ESGO Breast angiosarcoma: experience of a Tunisian anti-cancer center JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A216 OP A216 DO 10.1136/ijgc-2022-ESGO.466 VO 32 IS Suppl 2 A1 Takoua Chalouati A1 Montassar Ghalleb A1 Amani Jellali A1 Ines Zemni A1 Sarra Ben Ltaief A1 Riadh Chargui A1 Khaled Rahal YR 2022 UL http://ijgc.bmj.com/content/32/Suppl_2/A216.2.abstract AB Introduction/Background Breast angiosarcoma is rare and aggressive. It accounts for less than 1% of all breast malignancies. It can be developed after external beam radiation therapy or de novo. It has no distinguishing clinical or radiological characteristics, and it is commonly mistaken with other benign tumors.Methodology We describe seven cases of primary breast angiosarcoma: 6 cases occurred de novo, and one case occurred after external radiation, collected from 1995 to 2022 in our institution.Results The median age at the diagnosis was 53 years. The tumor size ranges from 1 to 11 cm. Breast ecchymosis was noticed in one case, while six patients presented a palpable mass. Breast imaging didn’t show any pathognomic signs. The histological diagnosis was based on the positivity of endothelial markers CD31 and vimentin. One patient had a history of invasive breast carcinoma, initially treated by conservative surgery followed by radiotherapy. Ten years later, she developed an ipsilateral angiosarcoma. Mastectomy was performed. After five months, she developed a recurrence, treated with an excision followed by chemotherapy. Six cases were primary angiosarcoma: 4 patients had a mastectomy. Local recurrences were noted in 2 of them, respectively, after 6 months and 1 year. They had wide excision and flash radiation. The rest of the patients had a lumpectomy with free margins. One of them had 5 years follow-up with no sign of recurrence.2 patients had pulmonary metastasis. They had chemotherapy; one died after 1 month, and the other is lost of follow-up.Conclusion The diagnosis of breast angiosarcoma is challenging, as it is frequently mistaken with other benign lesions. Physicians should be aware and consider the diagnosis even when confronted with a benign tumor clinical presentation. Treatment consists on mastectomy and radiation therapy without axillary dissection.