Synchronous bilateral breast carcinoma with different biological behaviors

case report

Abstract

Bilateral synchronous breast carcinoma (BSBC) is defined by the simultaneous presence of two prima- ry tumors at diagnosis. This is a case report of a female patient, aged 55 years, Caucasian, who sought a mastology service because of a lesion in the right breast (RB). In physical examination, a lump in the RB was noticed in the superolateral quadrant (SLQ ), as well as retraction and skin ulceration, with a palpable irregular mass of 5 cm, without nipple discharge, abnormal axillary lymph node, and stage III (T4b N1 Mx). Left breast (LB) was normal. Mammography showed suspicious lump in SLQ of RB (BI-RADS V), LB with monomorphic calcifications (BI-RADS II). MRI revealed a solid heteroge- neous nodule (3 cm) in SLQ of RB (BI-RADS V) and an irregular solid nodule (7 mm) in inferolateral quadrant (ILQ) of LB (BI-RADS V). Metastasis was not found on other tests. Biopsy revealed invasive ductal carcinoma in RB and ductal carcinoma in situ in LB, compatible with BSBC. On LB, the immu- nohistochemistry showed positive estrogen and progesterone receptors, negative for CERB-B2 and Ki-67 positive nuclear expression in 5% of tumor cells. RB presented triple-negative receptors and Ki-67 posi- tive in 10%. After neoadjuvant chemotherapy, a right mastectomy with axillary lymphadenectomy and left quadrantectomy with sentinel lymph node was performed. Anatomopathological exam of RB showed residual ductal carcinoma, free surgical margins and lymph nodes. In LB, sentinel lymph node was disease free and there was a complete pathological response. Treatment was continued with radiotherapy and Tamoxifen. Currently, the medical literature on the BSBC is scarce, thus hampering the therapeutic management in cases where each tumor displays different biological characteristics.