Neuroendocrine Tumors: Imaging of Treatment and Follow-up

Neuroendocrine tumors of the gynecological tract: A narrative literature review

Neuroendocrine neoplasms (NENs) of the gynecological tract are a rare, heterogenous and aggressive group of neoplasms, with high recurrence rates and poor prognosis. In this review we focus on NENs of the gynecological system emphasizing the classification, epidemiological and clinical characteristics of NENs across the gynecological tract (cervix, endometrium, ovary, vagina, and vulva), risk/prognostic factors, pathology and molecular biology (including actionable genomic mutations), imaging, staging and the most effective treatment modalities in the "standard of care" approach as well as the pipeline products. We also focused on metastatic spreading patterns of gynecological NENs. We searched for all available literature reviews, interventional studies, short series, case reports and meta-analyses published from 1990 to 2024. Deteriorated survival rate is essentially impacted by early development of lymph node, distant organ metastases and vascular propagation toward rapid extra-pelvic metastasis to the brain, liver, lung, bone marrow, lymph nodes and bones. Management of NENs needs to be customized on a case-based manner and comprises a multidisciplinary approach that involves gynecologists, surgeons, medical oncologists, radiologists, radiation oncologists, nuclear medicine specialists, pathologists, molecular biologists, qualified nurses etc. The treatment of extrapulmonary NENs arising in the female genital tract is basically extrapolated from that for small cell lung cancer. This includes, but is not limited to: surgery, chemotherapy, radiotherapy, peptide receptor radionuclide therapy, somatostatin analogs, and immunotherapy as well as investigational drugs in rare prospective clinical trials. Establishing modern therapeutic thesaurus is conditioned by the existence of well-designed clinical trials targeting a tumor's genomic profile and the incorporation of these data into the actual treatment landscape.

Neuroendocrine Neoplasms of the Gynecologic Tract

Simple Summary

Neuroendocrine refers to the cells that synthesize and secrete messenger chemicals such as neuropeptides and amines. Neuroendocrine neoplasms (NENs) are aggressive tumors arising from neuroendocrine cells, with an annual incidence of 6.98/100,000 and a prevalence of 170,000 in the United States. Primary gynecologic NENs constitute ≤2% of female reproductive tumors. NENs of the gynecologic tract are associated with high recurrence rates and dismal prognosis, making their treatment challenging. This article focuses on the updated staging classifications, clinicopathological characteristics, imaging, and management of NENs of the gynecological tract.

Abstract

Gynecological tract neuroendocrine neoplasms (NEN) are rare, aggressive tumors from endocrine cells derived from the neuroectoderm, neural crest, and endoderm. The primary gynecologic NENs constitute 2% of gynecologic malignancies, and the cervix is the most common site of NEN in the gynecologic tract. The updated WHO classification of gynecologic NEN is based on the Ki-67 index, mitotic index, and tumor characteristics such as necrosis, and brings more uniformity in the terminology of NENs like other disease sites. Imaging plays a crucial role in the staging, triaging, restaging, and surveillance of NENs. The expression of the somatostatin receptors on the surface of neuroendocrine cells forms the basis of increasing evaluation with functional imaging modalities using traditional and new tracers, including ⁶⁸Ga-DOTA-Somatostatin Analog-PET/CT. Management of NENs involves a multidisciplinary approach. New targeted therapies could improve the paradigm of care for these rare malignancies. This article focuses on the updated staging classifications, clinicopathological characteristics, imaging, and management of gynecologic NENs of the cervix, ovary, endometrium, vagina, and vulva, emphasizing the relatively common cervical neuroendocrine carcinomas among these entities.

Neuroendocrine neoplasia and bone (Review)

This is a narrative review focusing on neuroendocrine neoplasia (NEN) and bone status, in terms of metastases and osteoporosis/fractures. One fifth of NEN have skeletal dissemination, this affinity being regulated by intrinsic tumor factors such as the C-X-C chemokine receptor 4 (CXCR4). Bone colonization impairs the patient quality of life, representing a surrogate of reduced survival. Patients with NEN without bone metastases may exhibit low bone mineral density, perhaps carcinoid-related osteoporosis, yet not a standardized cause of osteoporosis. Case-finding strategies to address bone health in NEN with a good prognosis are lacking. Contributors to fractures in NEN subjects may include: menopausal status and advanced age, different drugs, induced hypogonadism, malnutrition, malabsorption (due to intestinal resection, carcinoid syndrome), hypovitaminosis D, impaired glucose profile (due to excessive hormones such as glucagon, somatostatinoma or use of somatostatin analogues), various corticoid regimes, and high risk of fall due to sarcopenia. Pheocromocytoma/paraganglioma involve bone through malignant forms (bone is an elective site) and potential secondary osteoporosis due to excessive hormonal content and increased sympathetic activity which is a key player of bone microarchitecture/quality as reflected by low Trabecular Bone Score. Glucocorticoid osteoporosis is related to NEN-associated ectopic Cushing syndrome. Currently, there are a lack of studies to emphasis that excessive gut-derivate serotonin in NENs with carcinoid syndrome is a specific activator of bone loss thus a contributor to carcinoid-related osteoporosis.

Adrenocorticotropic hormone-dependent hypercortisolism caused by pancreatic neuroendocrine carcinoma: A thought-provoking but remorseful case of delayed diagnosis

INTRODUCTION AND IMPORTANCE

Definitive diagnosis of functioning neuroendocrine neoplasms (NENs) in the pancreas is challenging. Adrenocorticotropic hormone (ACTH) regulates adrenal cortisol production. Ectopic ACTH secretion by functioning NENs may cause hypercortisolism.

PRESENTATION OF CASE

A 62-year-old woman who was receiving medications for hypertension and hyperlipidemia was referred to our hospital because of abnormal blood tests. Diabetes mellitus was initially diagnosed. Dynamic computed tomography and endoscopic ultrasound revealed a 35-mm diameter hypovascular tumor in the distal pancreas and multiple liver metastases. Endoscopic ultrasound-guided fine-needle aspiration resulted in a diagnosis of neuroendocrine carcinoma. The patient developed pancreatic leakage progressing to peritonitis, abscess formation, pleural effusion, and ascites after the fine-needle aspiration biopsy. Her clinical condition deteriorated to a septic state, necessitating emergency surgery comprising distal pancreatectomy, intraperitoneal lavage, and drainage. Wound healing was protracted and accompanied by ongoing high white blood cell counts and neutrophilia. She also developed a gastric ulcer postoperatively. Systematic endocrine investigations were performed because hypercortisolism caused by a functioning NEN was suspected. Eventually, a definitive diagnosis of an ACTH-producing NEN in the pancreas was made. Systemic chemotherapy was proposed; however, the patient and her family opted for palliative treatment only. She died 42 days after the initial diagnosis.

CLINICAL DISCUSSION

We here present a patient with ACTH-dependent hypercortisolism attributable to a pancreatic NEN who died of progressive cancer after a delay in definitive diagnosis.

CONCLUSION

Detailed investigation, including systematic endocrine examination and functional imaging studies, are important for precise diagnosis of, and appropriate treatment for, NENs.