[Neuroendocrine neoplasms of the breast]

Invasive Breast Carcinoma with Neuroendocrine Differentiation: A Single-Center Analysis of Clinical Features and Prognosis

Introduction Invasive breast cancer with neuroendocrine differentiation is a rare subtype of breast malignancy. Due to frequent changes in the definition of these lesions, the correct diagnosis, estimation of exact prevalence, and clinical behaviour of this entity may be challenging. The aim of this study was to evaluate the prevalence, clinical features, and outcomes in a large cohort of patients with breast cancer with neuroendocrine differentiation.

Patients Twenty-seven cases of breast cancer with neuroendocrine differentiation have been included in this analysis. Twenty-one cases were identified by systematic immunohistochemical re-evaluation of 465 breast cancer specimens using the neuroendocrine markers chromogranin A and synaptophysin, resulting in a prevalence of 4.5%. A further six cases were identified by a review of clinical records.

Results Median age at the time of diagnosis was 61 years. 70% of patients had T2 – 4 tumors and 37% were node-positive. The most common immunohistochemical subtype was HR-positive/HER2-negative (85%). 93% were positive for synaptophysin and 48% for chromogranin A. Somatostatin receptor type 2A status was positive in 12 of 24 analyzed tumors (50%). Neuroendocrine-specific treatment with somatostatin analogues was administered in two patients. The 5-year survival rate was 70%.

Conclusions Breast cancer with neuroendocrine differentiation is mostly HR-positive/HER2-negative and the diagnosis is made at a higher TNM stage than in patients with conventional invasive breast carcinoma. Moreover, breast cancer with neuroendocrine differentiation was found to be associated with impaired prognosis in several retrospective trials. Due to somatostatin receptor 2A expression, somatostatin receptor-based imaging can be used and somatostatin receptor-targeted therapy can be offered in selected cases.

Primary Neuroendocrine Neoplasms of the Breast: Case Series and Literature Review

Primary neuroendocrine carcinoma of the breast (NECB) as defined by the World Health Organization (WHO) in 2012 is a rare, but possibly under-diagnosed entity. It is heterogeneous as it entails a wide spectrum of diseases comprising both well-differentiated neuroendocrine tumors of the breast as well as highly aggressive small cell carcinomas. Retrospective screening of hospital charts of 612 patients (2008–2019) from our specialized outpatient unit for neuroendocrine neoplasia revealed five patients diagnosed with NECB. Given the low prevalence of these malignancies, correct diagnosis remains a challenge that requires an interdisciplinary approach. Specifically, NECB may be misclassified as carcinoma of the breast with neuroendocrine differentiation, carcinomas of the breast of no special type/invasive ductal carcinoma, or a metastasis to the breast. Therefore, this study presents multifaceted characteristics as well as the clinical course of these patients and discusses the five cases from our institution in the context of available literature.

Triple receptor-positive primary neuroendocrine carcinoma of breast in a young patient

Primary neuroendocrine carcinoma of breast is a very rare malignancy and preoperative diagnosis is difficult by clinical examination alone.Most oftenly, histopathological examination (HPE) and immunohistochemistry (IHC) studies are required to establish the diagnosis. We describe here a case of a primary neuroendocrine carcinoma of right breast in a 32-year-old woman. The patient underwent a right modified radical mastectomy, and the diagnosis was conclusively established postoperatively by the HPE and IHC reports. The IHC report revealed positive status of oestrogen, progesterone and Herceptin receptors.

Primary Neuroendocrine Breast Carcinoma in a 13-Year-Old Girl: Ultrasonography and Pathology Findings

Neuroendocrine carcinoma (NEC) of the breast is a rare disease and has been scarcely reported by African authors. The authors report a case of breast NEC in a 13-year-old African girl initially diagnosed as an atypical adenofibroma by ultrasonography. Ultrasound-guided biopsy and conventional histological examination indicated two potential diagnoses: primary malignant non-Hodgkin's lymphoma and undifferentiated carcinoma. According to immunohistochemistry performed on paraffin blocks in France, infiltrating ductal carcinoma with a strong neuroendocrine component was confirmed by CD56, CD57, and chromogranin A markers.