Secretory Carcinoma of the Breast: Report of Two Cases and Review of the Literature

Advancement of secretory breast carcinoma: a narrative review

BACKGROUND AND OBJECTIVE

Secretory breast carcinoma (SBC) is a rare breast malignancy. Most available studies on SBC are case reports or small case series, and the few large-sample studies available lack critical information due to database limitations. To improve the understanding of SBC and provide a reference for clinical practice, we systematically reviewed the demographic, clinical, pathologic, and genetic characteristics of SBC, as well as its treatment and prognosis.

METHODS

We conducted a PubMed search with the keywords "secretory breast carcinoma" or "juvenile breast carcinoma". Relevant English-language publications published from January 1966 to February 2022 were screened manually at 3 levels-title, abstract, and full text-to identify the articles that presented the demographic, clinical, pathologic, and genetic characteristics of SBC, as well as its treatment and prognosis.

KEY CONTENT AND FINDINGS

SBC lacks specific clinical manifestations and has typical pathological and molecular characteristics, including intracellular and extracellular eosinophilic secretions, immune spectrum similar to hormone receptor-positive tumors, and the ETV6-NTRK3 fusion gene. Surgery remains the primary treatment for SBC. Postoperative radiotherapy is recommended by most researchers for adult SBC but not for pediatric patients. The evidence of chemotherapy and endocrine therapy is insufficient, and targeted therapy of the ETV6-NTRK3 fusion gene shows a good response. Most patients with SBC have a good prognosis except for a few patients who experience distant metastases. Future studies will be focused on the molecular characteristics of those patients with SBC who have a poor prognosis.

CONCLUSIONS

The development of histopathology and molecular genetics has promoted the progress of the clinical diagnosis of SBC. The purpose of this review is to serve as a guide for the better clinical treatment of SBC, particularly in the areas of disease identification and prognosis classification for patients.

Secretory carcinoma of the breast with multiple distant metastases in the brain and unfavorable prognosis: a case report and literature review

Background

Secretory carcinoma of the breast is one of the rarest entities, accounting for less than 0.15 % of all infiltrating breast carcinomas. It has characteristic histopathological and molecular features and, in general, a more favorable prognosis. In this case report, we describe a local, advanced secretory carcinoma of the breast with aggressive course and an unfavorable outcome.

Case presentation

A hard, painless, and palpably bossed mass approximately 12.0 cm in diameter occupied most of the left breast of a 39-year-old woman with fixation to the overlying skin. Breast ultrasonography and magnetic resonance imaging (MRI) scans gave the same grading as BI-RADS IV. A needle biopsy was performed, and the pathological diagnosis was secretory carcinoma. Neoadjuvant chemotherapy (NAC) was then performed, after which ultrasonography and MRI scans revealed chemo-resistance of the tumor to NAC. Left breast mastectomy and axillary lymphadenectomy were subsequently performed. Tumor cells were triple-negative and positive for S-100 and periodic acid-Schiff (PAS) staining. Fluorescence in-situ hybridization (FISH) analysis indicated a fusion arrangement of the ETV6-NTRK3 gene. The patient developed multiple distant metastases in the brain and died of these metastases 19 months after initial diagnosis.

Conclusions

Secretory carcinomas of the breast have been described as a low-grade histologic subtype with a favorable prognosis. This case showed chemo-resistance to neoadjuvant chemotherapy, multiple distant metastases, and a final unfavorable outcome. Further research is needed to better understand the behavior and treatment of this rare tumor.

Clinicoradiologicial aspects of secretory carcinoma breast: A rare pediatric breast malignancy

Secretory carcinoma (juvenile carcinoma) is one of the very rare breast malignancy reported to be prevalent in pediatric age group. We report imaging and clinicopathological features of secretory carcinoma breast with distant and axillary metastasis, in an 11-year-old girl, who presented with a painful lump in right breast. Ultrasound revealed a well-defined, partially microlobulated hypoechoic mass with skin and pectoralis muscle involvement and a suspicious morphology right axillary lymph node. Color Doppler revealed increased vascularity in both the breast mass and suspicious axillary node. Magnetic resonance imaging helped in better evaluation of pectoralis muscle involvement. Computed tomography (CT) neck, chest, and abdomen revealed multiple fibronodular opacities in bilateral lung fields. 18 Flouro-Deoxy-Glucose Positron Emission Tomography (FDG PET-CT) showed a hypermetabolic retroareolar breast mass with multiple hypermetabolic bilateral lung nodules suggesting lung metastasis. The histopathology confirmed the diagnosis of secretory carcinoma. The patient was offered chemotherapy for 2 years and put on follow-up since then.