495 - RECURRENT PHYLLODES TUMOR MALIGNANCY: A CASE REPORT

Resumo

Fibroepithelial tumors of the breast are part of a heterogeneous group of biphasic neoplasms, which include common
fibroadenomas (FA) and phyllodes tumors (PTs). The PT is a rare fibroepithelial tumor that is histologically divided into
three grades: benign, malignant, or borderline. Although only about 10% of these tumors are malignant, even benign
tumors are prone to local recurrence and can become very large in size. The standard management of PT is surgical excision with negative surgical margins, due to the propensity for local recurrence. Therefore, the report about this type of
tumor with multiple recurrences and malignization in the same person is important for the literature. A female patient,
30 years old, without comorbidities, with an obstetrical history of an abortion due to anembryonic egg and with a previous
oncological history of four left breast segmental resections for the removal of solid nodules, confirmed anatomopathologically as borderline PT, benign PT, FA, and benign PT, respectively, in the years 2017, 2018, 2018, and 2019, was observed.
No intercurrences were noted in the follow-up with a mastologist who found, in the physical examination, the presence
of nodules and a palpable left breast, which caused discomfort when lying in the left decubitus position, with painless,
nonsecretive, without palpable lymph nodes, and with accelerated growth. Ultrasonography revealed the presence of simple cysts in the right breast and two solid nodules BI-RADS 4 compatible with the diagnostic hypothesis of PT; therefore,
surgical resection was indicated. However, with the increase in the volume of the nodules, it was not possible to obtain
free margins and a simple mastectomy was chosen. On November 11, 2021, a left mastectomy was performed with partial
resection of the pectoralis major muscle due to an intraoperative infiltrative lesion and immediate breast reconstruction
with the placement of silicone prosthesis, without complications. In the anatomopathological examination, a malignant
PT was identified with an infiltrative border pattern and the presence of neoplastic infiltration in the underlying skeletal
muscle tissue. On December 23, 2021, the oncologist informed that the CT-PET performed days before denoted the absence
of sites suggestive of a neoplastic process and the presence of a probable inflammatory scarring process in the left breast
around the breast prosthesis. She is currently being followed up by the mastologist and the oncologist, through imagining examinations together with the clinical consultation, without the use of chemotherapies.