Rare Occurrence of a Poorly Differentiated Neuroendocrine Tumor of the Bladder

Primary Neuroendocrine Tumor of the Breast: Current Understanding and Future Perspectives

Primary neuroendocrine carcinoma of the breast (NECB) is characterized with heterogeneity, rarity, and poor differentiation, which is probably an underestimated subtype of breast cancer, including small cell NECs and large cell NECs. The diagnostic criteria for NECB have been constantly updated as the disease changes and the understanding increases. According to the latest WHO Classification, primary neuroendocrine neoplasm (NEN) of the breast consists of well-differentiated neuroendocrine tumors (NET), extremely aggressive neuroendocrine carcinomas (NEC) as well as invasive breast cancers of no special type (IBCs-NST) with neuroendocrine differentiation. The accurate diagnosis of NECB remains a challenge for its low incidence, which needs multi-disciplinary methods. For the rarity of the disease, there is a lack of large samples and prospective clinical research. For these invasive tumors, there are no standardized therapeutic guidelines or norms, and the treatment often refers to nonspecific breast cancer. In addition, the prognosis of such patients remains unknown. In 2003, the World Health Organization (WHO) listed NECB as an independent entity for the first time, while few features of NECB were clarified. In this review, it presents the WHO Classification, clinicopathologic characteristics, diagnosis, treatment, and prognosis of these patients. In addition, it summarizes the latest studies on molecular features of NECB, aiming to provide new therapeutic perspectives for the disease.

Primary MiNEN of the urinary bladder: an hitherto undescribed entity composed of large cell neuroendocrine carcinoma and adenocarcinoma with a distinct clinical behavior : Description of a case and review of the pertinent literature

Neuroendocrine carcinomas (NECs) of the urinary bladder are very rare and can be observed in the context of mixed neuroendocrine/non-neuroendocrine neoplasms (MiNENs), most frequently in association with urothelial carcinoma. Small cell NECs are far more common than large cell NECs (LCNECs), which are exceedingly rare. We describe a primary MiNEN of the urinary bladder, composed of a LCNEC and of an adenocarcinoma, in which the neuroendocrine component reached complete pathological regression after neoadjuvant M-VAC chemotherapy, whereas the non-neuroendocrine component of the tumor progressed to metastatic disease. Compared to mixed neuroendocrine/non-neuroendocrine neoplasms described in the literature until now, this appears to be a unique case that expands the spectrum of neuroendocrine neoplasia of the urinary bladder.

Large Cell Neuroendocrine Carcinoma of the Bladder with Adenocarcinomatous Component

Large cell neuroendocrine carcinoma (LCNC) is one of the rarest types of bladder cancer occurring in <1%. Either pure or mixed with another component, it remains one of the most aggressive types of bladder cancer. We report a case of LCNC of the bladder with an adenocarcinomatous component. The patient was a 64-year-old smoker male, who presented for the first time with dysuria and hematuria. A bladder tumor invading the anterior and right lateral bladder walls was discovered, without any secondary localizations. Tumor biopsy showed an LCNC with adenocarcinomatous components. The patient was treated by recurrent tumor resections, chemotherapy, and radiotherapy. No improvement was noted despite close follow-up and adequate treatment. Neuroendocrine bladder tumor is known to have an aggressive, rapid, and disadvantageous evolution. Multiple case reports were published so far, and a recent review was conducted in March 2020 by Sanguedolce et al. (2020). More cases are needed to establish the best management plan for this type of tumor.

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.

Pure large cell neuroendocrine carcinoma of the bladder without urological symptoms

Neuroendocrine carcinoma is one of the uncommonly seen pathologies of the urinary bladder. Macroscopic hematuria is frequently encountered symptom in patients with neuroendocrine carcinoma. We report a 45-year-old man with left solitary kidney and oliguria for five days the development of acute renal failure (ARF) with the impaired general condition. The underlying cause being identified as pure type large-cell neuroendocrine carcinoma of the bladder. Large-cell neuroendocrine carcinoma of the bladder is an uncommon fatal tumor. No macroscopic hematuria or urological symptom was observed in our case. Advanced ectasia was not observed in the kidney, and the patient's clinical status was complicated with ARF. It must not be forgotten that in some bladder tumors, the patient's general condition may be impaired without urological symptoms.