Carcinoma micropapilar invasivo de mama: tratamiento de doble bloqueo con Trastuzumab-Pertuzumab, a propósito de un caso

Abstract

Introduction: Invasive Micropapillary Carcinoma (IMPC) is a histological type of infiltrating ductal carcinoma with a poor prognosis due to its high lymphotropism, frequent lymph node involvement, high tissue incidence independent of tumor size, and micropapillary component. Understanding the effectiveness of double blockade therapy with monoclonal antibodies (mAbs) as Neoadjuvant Therapy for IMPC is essential, with high levels of the human epidermal growth factor receptor 2 (HER2) protein. A case of a 49-year-old mestizo patient with a tumor in the upper-outer quadrant (UOQ) of the right breast is reported. After complementary examinations, IMPC was diagnosed with a histological score of Nottingham: 2 (tubular differentiation 2, nuclear pleomorphism 2, mitosis 2). ER immunohistochemistry: positive 10%; PR: positive 5%; P53: negative; KI-67: positive 14%; E-cadherin: positive; HER2: 3+. MRI shows a mass with irregular edges and spiculated contours measuring 60x30x33mm. In the right axillary region, the presence of two lymph nodes with heterogeneous contrast enhancement indicated an occupational process with signs of malignancy, classified as BI-RADS VI, according to the Tumor, Node, Metastasis (TNM) system, the staging was T3 N1c M0, corresponding to stage III A. Neoadjuvant Chemotherapy with cytostatics and double blockade therapy directed at the HER2 protein with monoclonal antibodies was initiated. After completing the respective therapy cycles, sentinel lymph node identification was performed with EtO + right breast lumpectomy. Conclusions: In this case, it was possible to demonstrate the effectiveness of double blockade therapy with mAbs as Neoadjuvant Therapy to achieve a complete pathological response (CPR), which allows for breast-conserving surgery.