Giant Borderline Phyllodes Breast Tumor in Pregnancy

Abstract

INTRODUCTION: Phyllodes is a rare breast tumor that grows rapidly and to a large size, being exceedingly rare during pregnancy. These tumors may be classified as benign, borderline or malignant. Up until now there is no report in the literature of a borderline phyllodes arising during pregnancy. CASE REPORT: a 29 years old white female patient at the 15th week of pregnancy presented with a large mass in left breast that have been growing for 6 months. The patient had a previous history of osteossarcoma in the left jaw five years before. At physical exam there was a protruding and hardened palpable mass occupying the whole left breast. There were no signs of cutaneous involvement or axillary lymphadenomegaly. In the right breast there were two palpable mobile tumors. She did not had a mammogram because of the size of the tumor. Ultrasound showed four nodules in the right breast. The largest one measured 5 cm in diameter. In the left breast there were confluent masses with well-defined margins, with heterogeneous echotexture, cystic areas and posterior acoustic enhancement. Ultrasound-guided percutaneous biopsy was performed in both breasts. The correspondent histophatological examination revealed a biphasic fibroepithelial lesions with atypical stromal component that were classified as borderline lesions. After these results, patient underwent mas¬tectomy without axillary dissection on the left side and tumorectomy on the right breast. Anatomopathologic analysis of the surgical specimen of left breast revealed a 20x10 cm necrotic tumor. In the right breast three rounded nodules were found. All lesions were classified as borderline phyllodes tumors. Surgical margins were free of tumor. DISCUSSION: Phyllodes are extremely rare during pregnancy. There are only eight cases reported to this date, all classified as malignant. To the best of our knowledge, we report here the first case of a borderline phyllodes occurring in pregnancy. It is unknown if these tumors are hormone dependent. The aim of treatment is to perform a wide resection with free margins. The adjuvant treatment for borderline phyllodes tumors is not yet defined.