Invasive Lobular Carcinoma of the Breast Arising in A Fibroadenoma: A Case Report

Abstract

INTRODUCTION: Fibroadenomas are benign tumors of the breast, relatively common, found at any age but with higher incidence in the second and third decades. Although fibroadenoma is generally considered benign, there is evidence for an association with complex fibroadenomas and an increased risk of breast cancer, which occurs usually in fifth decade. Chater and Culter were the first to describe a carcinoma arising in a fibroadenoma, which incidence is 0, 5% of all fibroadenomas. CASE REPORT: A latin-american 52 year-old woman, from Rio de Janeiro, Brazil, had a mamography screening with Bi-Rads 0 as result, in December 2011. Further investigation was done with an ultrasound that found bilateral solid nodes being three of them described as Bi-Rads 4. These nodes were located in the right breast at retroaerolar tissue, measuring 20, 7x19, 5mm, another at upper outer quadrant, measuring 8, 5x7, 2mm and the third at the junction of outer quadrants measuring 13, 3x11, 4mm. Other solid nodes were found at contralateral breast caracterized as Bi-Rads 3. At physical examination was observed a 45mm node in the retroareolar tissue in the right breast and a 10mm node in the junction of outer quadrants. In March 2012 the patient had a core biopsy of the biggest node described above. The histopathological diagnosis was invasive Lobular carcinoma in a fibroadenoma. The imunohistochemical results showed a tumor with positive estrogen receptor, negative progesterone receptor and Her-2 score was 0. After the diagnosis in the right breast, were realized core biopsies of the three biggest nodes in the left breast. The histopathological results showed benign fibroepithelial neoplasia. In May 2012, the patient was submited to a right skin sparing mastectomy with right sentinel node biopsy and imediate reconstruction of the breast with expander, simultaneously was submited to a tumorectomy guided by ultrasound of the four solid nodes in the left breast. In the right breast was confirmed the diagnosis of multicentric invasive Lobular carcinoma with surgical limits free of malign cells. In the left breast was found fibroadenoma, adenosis and florid ductal DISCUSSION: Fibroadenomas are common benign lesions of the breast that usually present as a single breast mass in young women. Simple fibroadenomas have a reported incidence of 7-13% in women from adolescence through the mid 20s. The incidence of carcinoma arising in a fibroadenoma is reported to be 0, 5%, which occur usually in the fifth decade. Two-thirds of carcinomas within fibroadenoma are Lobular and one-third are ductal or mixed ductal and Lobular. Complex fibroadenomas and proliferative disease adjacent to fibroadenoma are associated with a slight increase in the risk of breast cancer. Detection of malignancy developing within a fibroadenoma can be difficult. In this case, imaging exams showed suspicious lesions that deserved investigation.