Secretory Carcinoma of the Breast: An Elusive Presentation of This Rare Pathology

Abstract

terial, samples are strongly S-100 protein reactive. Secretory breast carcinoma is driven by the fusion gene ETV6-NTRK3 that results from a balanced translocation t (12; 15) [6].Fortunately for most diagnosed with SBC, the course is indolent even in the setting of nodal metastasis, which is present in 15-35% cases at presentation [2,3,7]. Although distant metastasis is very rare, local recurrence is described, recurring as far as 16 years after treatment [8]. At present the primary treatment remains surgical. Case ReportA 75-year-old female presented to our clinic with complaint of new onset right nipple pain and swelling for 4 weeks. Family history was significant for breast cancer in a maternal and a paternal first cousin, as well as a maternal aunt who succumbed to her disease at age 50. The initial physical exam revealed a tender, erythematous, enlarged right nipple, but no palpable masses. The initial impression was mastitis, and she was started on azithromycin. A diagnostic mammogram showed asymmetry of the right nipple compared to the left ( Figure 1), however, ultrasound at that time was unremarkable. Her symptoms did not improve with antibiotics.A repeat targeted ultrasound of this area revealed an abnormal right nipple complex (Figure 2). She was then assessed by a breast surgeon, and the exam at that time revealed a firm, tender, erythematous mass of the superior aspect of the right nipple, and a palpable right axillary lymph node. Ultrasound-guided fine needle aspiration biopsy of the axillary node was consistent with metastatic adenocarcinoma. The tumor stained positive AbstractSince first being noted in the literature in 1966, Secretory Breast Carcinoma (SBC) continues to be better defined in terms of its clinical, histologic, and genetic features. However, its unique presentation can elude seasoned practitioners from making a clinical diagnosis. Furthermore, there is neither consensus nor guidelines as to the optimal treatment approach for SBC. We are presenting this case report and literature review to raise awareness about SBC by demonstrating how uniquely this pathology can present itself, to summarize the current literature, and to present our specific approach to this rare cancer.

Metastatic triple negative breast cancer with NTRK gene fusion on tissue but not on ctDNA molecular profile

“…The TNBC has an increased likelihood of distant recurrence and death, with the risk of recurrence peaking at 3 years and the median survival of 13.3–18 months in the metastatic setting 10–12. By comparison, the 5-year survival rate for SBC is 87.2–93.2%, with a greater likelihood of survival in its juvenile form 13 14…”