Primary renal neuroendocrine neoplasms: A systematic literature review, report of four local cases, and original survival analysis of 63 patients from a national registry 2012-2018

Pathogenesis, diagnosis and treatment of primary renal well-differentiated neuroendocrine tumors: a review of the literature

Neuroendocrine tumors (NETs) are a rare type of neoplasm that originate from neuroendocrine cells and peptide neurons. Primary renal well-differentiated NETs are extremely rare, and only a few cases have been reported worldwide. In this study, we present a new case of primary renal well-differentiated NET at our institution, followed by a literature review. A systematic search was conducted using various search terms to identify relevant literature on primary renal well-differentiated NETs from 2021 to present. The study analyzed the clinical features, age, gender, tumor size, location, gross pathology, light microscopy, and immunohistochemical results of 32 cases of primary renal well-differentiated NETs. The findings suggest that these tumors are rare and have nonspecific clinical and imaging features. The diagnosis heavily relies on immunohistochemical analysis. Primary renal well-differentiated NETs are associated with low malignant potential and a favorable prognosis. Surgical resection is the preferred treatment, and long-term follow-up is necessary to monitor the patient's condition.

Hepatic cytoreduction for lung and renal neuroendocrine tumor metastases

BACKGROUND

Patients with hepatic metastases from lung and renal neuroendocrine tumors are rare. Outcome data on treatment of hepatic metastases for these types of tumors are lacking. We report the outcomes of hepatic cytoreduction operations for these tumors.

METHODS

Records of patients undergoing hepatic cytoreduction operations of at least 70 ​% of the hepatic tumors for well differentiated lung and renal neuroendocrine tumors were reviewed. Data collected included primary tumor type, number and size of metastases resected, tumor grade, percentage of hepatic cytoreduction, presence of extra-hepatic disease, and status at last follow up.

RESULTS

Twenty-one patients were identified. Ninety percent had extrahepatic metastases. Median-time to liver progression was 66 months. The five-year survival rate was 65 ​%. Liver failure was the predominant cause of death. No prognostic factors for survival could be identified among the variables collected.

CONCLUSION

Hepatic cytoreduction operations for lung and renal neuroendocrine tumors do not yield as good of survival rates as observed with small bowel and pancreatic neuroendocrine tumors, but are considerably better than those obtained with complete resection of colorectal metastases.

Extrapulmonary Neuroendocrine Carcinomas: Current Management and Future Perspectives

Neuroendocrine carcinomas (NECs) are poorly differentiated and highly aggressive epithelial neuroendocrine neoplasms. The most common primary site is the lung, but they may arise in every organ. Approximately 37% of extrapulmonary NECs (EP-NECs) occur in the gastroenteropancreatic (GEP) tract, followed by the genitourinary (GU) system and gynecological tract. As a result of their rarity, there is scant evidence to guide treatment recommendations, and a multidisciplinary approach is essential for the management of such patients. Platinum-based chemotherapy currently represents the standard of care for EP-NECs of any site, mirroring the management of small-cell lung cancer (SCLC), but further approaches are still under investigation. Indeed, ongoing trials evaluating targeted therapies, immune checkpoint inhibitors (ICIs), and radionuclide therapy could provide potentially breakthrough therapeutic options. Given the relative dearth of evidence-based literature on these orphan diseases, the aim of this review is to provide an overview of the pathology and current treatment options, as well as to shed light on the most pressing unmet needs in the field.