SPONTANEOUS REGRESSION OF MALIGNANT BREAST NEOPLASM IN A PATIENT WITH HIGH LEVELS OF IMMUNOGLOBULIN E

M.C.V., 54 years old, born in Presidente Bernardes, Minas Gerais, was admitted on September 10, 2018, with a palpable abnormality in the right breast, a 15-mm heterogeneous lobular nodule in the junction of the right upper quadrants (BI-RADS 5). Mammography showed focal asymmetry in the same location (BI-RADS 0). She was submitted to ultrasound-guided core-needle biopsy with a result of invasive ductal carcinoma — grade 3. The immunohistochemical pattern revealed positive estrogen and progesterone receptors, C-ERB B2 with a +2 score, and 20% Ki67 positive. The FISH test was negative. The patient refused treatment, returning to the facility on August 14, 2019, with a normal physical examination. Ultrasound showed an 8 mm lesion in the junction of the right upper quadrants (BI-RADS 6), while mammography indicated focal asymmetry regression. A staging study was performed with chest x-ray, abdominal ultrasound, and normal bone scan. Laboratory study was normal, except for a high total IgE level of 4,290. She underwent segmental resection and sentinel lymph node biopsy in the right breast on August 17, 2019, at the Hospital São Vicente de Paula, Ubá/ Minas Gerais, with the histological result revealing a 9-mm invasive lobular carcinoma, free margins, and negative sentinel lymph node. The treatment indicated was radiotherapy and the use of 20 mg tamoxifen for 5 years. We conclude that there is something different, possibly associated with the high IgE level, which we will continue to study to understand.