Functional imaging in neuroendocrine tumors: assessment of molecular heterogeneity using [68Ga]Ga-DOTA-TOC and [18F]FDG PET/CT

OBJECTIVE

The aim of the study was evaluate the diagnostic performance of [68Ga]Ga-DOTA-TOC and [18F]FDG PET/CT in patients with histologically proven neuroendocrine tumors (NETs), as well as the correlation of the visualized findings with the tumor grade.

MATERIAL AND METHODS

We included 50 patients with NETs who underwent both [68Ga]Ga-DOTA-TOC and [18F]FDG PET/TC. The pooled sensitivity of both scans was compared, as well as [68Ga]Ga-DOTA-TOC and [18F]FDG for each tumor grade (grade 1/G1, grade 2/G2 and grade 3/G3). Also, the sensitivity of [68Ga]Ga-DOTA-TOC and [18F]FDG as a function of the continuous variable Ki-67 was investigated. Finally, the number of lesions detected by both PET radiopharmaceuticals for each tumor grade was compared.

RESULTS

The pooled sensitivity of both PET/CT (96%) was higher than [68Ga]Ga-DOTA-TOC (84%) and [18F]FDG (44%) separately, with statistically significant differences. The sensitivity of [68Ga]Ga-DOTA-TOC was higher than [18F]FDG in both G1 (p = 0.004) and G2 (p < 0.001). In G3 the performance of both scans detected disease in 100% of this subgroup. The sensitivity of [68Ga]Ga-DOTA-TOC and [18F]FDG PET/CT correlated significantly with the Ki-67 proliferative index. In G2 patients the number of lesions detected with [68Ga]Ga-DOTA-TOC was higher than [18F]FDG.

CONCLUSIONS

The performance of both PET/CT, particularly in G2 and G3, demonstrates the molecular heterogeneity of metastatic NETs and contributes to the selection of a more appropriate treatment, particularly in those high-grade patients who may benefit from radionuclide therapy (PRRT).

Discrepancy in the Ki67 labeling index of brain and orbital metastatic lesions from gastrointestinal neuroendocrine tumors: A case report

Proliferative activity examined by Ki67 labeling index (LI) plays pivotal role for managing gastrointestinal neuroendocrine tumor (GI-NET). Few reports indicated the intra-patient heterogeneity of Ki67-LI among metastatic tumor sites. We report a case of brain and orbital metastases from GI-NET that showed discrepancy of the Ki67-LI. A 71 year-old woman who was diagnosed as GI-NET with liver and bone metastases and performed medical therapy, had headache, right exophthalmos, and pain of right eye and was referred to our department. Magnetic resonance image revealed that tumors in the left occipital region and right orbit. We diagnosed as metastatic brain and orbital tumors from GI-NET. Surgical removal of both symptomatic lesions was performed and the diagnosis was pathologically confirmed. Immunohistochemical studies revealed the discrepancy of the Ki67-LI of the lesions (brain tumor: 8% versus orbital tumor: 22%). Sampling of multiple metastatic sites may prevent underestimate tumor proliferative activity.

[Neuroendocrine tumor associated with an intestinal cyst: a case report]

Intestinal (tailgut) cysts or retrorectal cystic hamartomas are rare benign lesions that are included in the category of developmental cystic lesions. Their origin is still uncertain, although several hypotheses have been proposed to explain their development. They are located mainly in the presacral (retrorectal) space and predominately affect middle-aged women (40-60 years). Taking into account location and histological characteristics, the main differential diagnoses include epidermoid cysts, duplication cysts and teratomas. Malignant transformation of these lesions is rare and preferentially into adenocarcinoma and neuroendocrine tumors. We present a case of an intestinal cyst associated with a well-differentiated neuroendocrine tumor (G1) in a 63-year-old woman.

Peptide receptor radionuclide therapy with [177Lu]Lu-DOTA-TATE

This continuing education aims to present in a clear and easy-to-understand way, the biology of neuroendocrine tumors (NETs), the characteristics of somatostatin receptors, the selection of patients for radiolabelled peptide therapy (PRRT), the inclusion criteria to benefit from treatment with the minimum possible adverse effects, the administration protocol, follow-up and response evaluation. The functional imaging studies necessary to explore the biology of the tumor and to individualize the treatment are also carried out, and constitute the cornerstone for the development of teragnosis. Clinical trials are being developed to better define the position of PRRT within the broad therapeutic options, and among the future perspectives, there are several lines of research to improve the objective response rate and survival with PRRT, focused on the development of new agonists and somatostatin receptor antagonists, new radionuclides and radiosensitizing combination therapies. In conclusion, PRRT is a great therapeutic, well-tolerated and safe tool with generally mild and self-limited acute side effects, that must be sequenced at the best moment of the evolution of the disease of patients with NET. Candidate patients for PRRT should always be evaluated by a multidisciplinary clinical committee.

Discrepancy in the Ki67 labeling index of brain and orbital metastatic lesions from gastrointestinal neuroendocrine tumors: A case report

Proliferative activity examined by Ki67 labeling index (LI) plays pivotal role for managing gastrointestinal neuroendocrine tumor (GI-NET). Few reports indicated the intra-patient heterogeneity of Ki67-LI among metastatic tumor sites. We report a case of brain and orbital metastases from GI-NET that showed discrepancy of the Ki67-LI. A 71 year-old woman who was diagnosed as GI-NET with liver and bone metastases and performed medical therapy, had headache, right exophthalmos, and pain of right eye and was referred to our department. Magnetic resonance image revealed that tumors in the left occipital region and right orbit. We diagnosed as metastatic brain and orbital tumors from GI-NET. Surgical removal of both symptomatic lesions was performed and the diagnosis was pathologically confirmed. Immunohistochemical studies revealed the discrepancy of the Ki67-LI of the lesions (brain tumor: 8% versus orbital tumor: 22%). Sampling of multiple metastatic sites may prevent underestimate tumor proliferative activity.

Neuroendocrine tumor associate with inflammatory bowel disease: two cases report

Introduction

Patients with inflammatory bowel disease (IBD) have a higher risk of developing gastrointestinal tumors, the adenocarcinoma is the most frequently associated, and neuroendocrine tumor (NET) the most rare.

Clinical cases

We present two patients, one with Crohn's disease and the other with ulcerative colitis, who present nonspecific symptoms, and after resection of an intestinal lesion, a gastrointestinal NET (GINET) is diagnosed.

Discussion and conclusion

The GINET have an insidious clinic and these can be confused with those of the IBD. There could be an association between both pathologies; an important role of the chronic intestinal inflammatory process is suggested. The best treatment for GINET is the resection.

[Tumores neuroendocrinos pancreáticos. Nuestra experiencia]

Pancreatic neuroendocrine tumors are rare. It is a heterogeneous group of neoplasms with very different behavior and prognosis. They can appear sporadically or associated with genetic syndromes. They are divided into functioning and non-functioning. A descriptive retrospective study of patients diagnosed with pancreatic neuroendocrine tumor was performed. The incidental diagnosis of these tumors is increasingly. The only curative treatment for these tumors is surgical excision, depending on the location and characteristics of the tumor and the patient. In selected cases a conservative attitude is recommended.

[Tumor neuroendocrino ano-rectal: desde un pólipo con buen pronóstico hasta un carcinoma letal]

Introducción

Aunque los tumores neuroendocrinos rectales son neoplasias poco frecuentes, su incidencia está aumentando en las tres últimas décadas. El objetivo de este trabajo es el estudio del comportamiento de dichos tumores basándonos en sus variables clínicas, diagnósticas, terapéuticas y anatomopatológicas en un hospital terciario.

Método

Estudio retrospectivo de los tumores neuroendocrinos rectales desde el año 2000 hasta el año 2017 en nuestro hospital. Se realizó una búsqueda informatizada en el programa SNOMED del servicio de anatomía patológica, empleando los criterios «tumor neuroendocrino» y «tumor carcinoide».

Resultados

Se hallaron 16 pacientes con tumor neuroendocrino ano-rectal. El 75% eran varones. La mediana de edad fue de 53 años (rango: 34-83). El diagnóstico fue incidental en el 62,5%. El tratamiento fue endoscópico en 13 (81%) pacientes y quirúrgico en 3 (19%). El 75% de las lesiones fueron T1. El 68,7% de los tumores presentaban un grado de agresividad G1. La media de seguimiento fue de 29 meses; no hubo recidivas. Durante el seguimiento fallecieron 3 (18,5%) pacientes, todos ellos con tumor G3 metastásico, y la supervivencia media fue de 8 meses.

Conclusiones

Los tumores neuroendocrinos rectales son cada vez más frecuentes y presentan unos patrones variables, cuyo pronóstico dependerá de su agresividad histológica. El aumento de su incidencia puede deberse a una mayor concienciación de la existencia de estos tumores, a las campañas de cribado del cáncer colorrectal, al aumento del número de colonoscopias realizadas y a la generalización de los estudios histológicos con marcadores neuroendocrinos.

Background

Although rectal neuroendocrine tumours are rare neoplasms, their incidence is increasing in the last three decades. The objective of this work is to study the behaviour of these tumours based on their clinical, diagnostic, therapeutic, and pathological variables in a tertiary hospital.

Method

Retrospective study of rectal neuroendocrine tumours from 2000 to 2017 in our hospital. A computerized search was performed in the SNOMED program of the pathological anatomy service, using the criteria “neuroendocrine tumour” and “carcinoid tumour”.

Results

We found 16 patients with ano-rectal neuroendocrine tumour; 75% were male. The median age was 53 years (range: 34-83). The diagnosis was incidental in 62.5%, with endoscopic treatment in 13 patients (81%) and surgical treatment in 3 (19%). 75% of the lesions were T1. 68.7% of the tumours showed a degree of G1 aggression. The mean follow-up was 29 months; no recurrences. During follow-up, three patients died (18.5%), all of them with metastatic G3 tumour and the mean survival was 8 months.

Conclusions

The rectal neuroendocrine tumours are increasingly frequent and present variable patterns, whose prognosis will depend on their histological aggressiveness. The increase incidence may be due to a greater awareness of the existence of these tumours, to colorectal cancer screening, to the increase in the number of colonoscopies performed and to the generalization of histological studies with neuroendocrine markers.

[Polymetastatic highly aggressive Small Cell Undifferentiated Neuroendocrine Carcinoma of Ascending Colon]

Neuroendocrine carcinoma (NEC) of the colon is a rare and very aggressive tumor with poor prognosis. The current case report presents a 53-year-old male with a 6 cm × 10 cm ascending colon carcinoma, causing large intestine obstruction, with simultaneous multiple hepatic metastases and peritoneal carcinomatosis. Surgical resection of the primary tumor was performed, because of the bowel obstruction, to ameliorate the symptoms before the onset of chemotherapy. Histopathology revealed that the tumor was a small-cell undifferentiated NEC. During the post0operative period, the patient presented pulmonary metastases, and on the 36th post-operative day, death occurred due to respiratory failure.

Ectopic Cushing syndrome: Report of 9 cases

INTRODUCTION

Ectopic Cushing's syndrome (ECS) is a rare condition caused by ACTH secretion by extrapituitary tumors. Its low frequency makes it difficult to acquire experience in its management. The aim of this study was to describe patients with ECS seen at the endocrinology department of a tertiary hospital over 15 years.

METHODS

This was a retrospective study of the clinical, biochemical and radiographic data, treatment, and course of patients with ECS seen from 2000 to 2015.

RESULTS

Nine patients (6 of them female) with a mean age of 47 years were included in the study. The clinical syndrome developed in less than 3 months in all cases but one, and most patients also had edema, hyperpigmentation and/or hypokalemia. Mean urinary free cortisol and ACTH levels were 2,840μg/24h and 204pg/mL respectively. The ectopic origin was confirmed by a combination of dynamic non-invasive tests and radiographic studies in most cases. The tumor responsible could be identified in 8 cases, and 7 patients had metastatic dissemination. Primary treatment was surgery in one patient, surgery combined with systemic therapy in 3, and chemotherapy in the other 3 patients. Bilateral adrenalectomy was required in 4 patients to control hypercortisolism. After a mean follow-up of 40 months, 3 patients died, 5 were still alive, and one had been lost to follow-up.

CONCLUSIONS

Our study confirms that ECS covers a wide spectrum of tumors of different aggressiveness and nature. The ectopic origin of Cushing's syndrome can usually, be suspected and confirmed in most cases without the need for invasive tests. Control of both hypercortisolism and the tumor requires multiple treatment modalities, and multidisciplinary management is recommended.

Primary well differentiated neuroendocrine tumor of the filum terminale. Case report and literature review

OBJECTIVE

To present a case of a well-differentiated primary intradural-extramedullary neuroendocrine tumor of the filum terminale and to conduct a literature review.

CASE

A 68-years old patient was assessed after presenting lower back pain and sciatica with ineffective pain relief. The patient presented an intradural-extramedullary lumbar lesion arising from the filum terminale, which was partially resected. The pathology diagnosis was a well-differentiated primary neuroendocrine tumor (carcinoid tumor). After a multidisciplinary evaluation, fractionated stereotactic radiotherapy was administered. No progression or metastatic spread was observed in successive assessments.

DISCUSSION

Neuroendocrine tumors are heterogeneous neoplasms derived predominantly from enterochromaffin cells, in which chemotherapy plays a very limited role. In contrast, radiotherapy has been described in partially resected lesions.

CONCLUSION

Well-differentiated primary neuroendocrine tumors with intradural-extramedullary lumbosacral location are an exceptional rarity. Isolated surgical resection, or associated with an adjuvant radiotherapy treatment in subtotal resections, could be considered an effective therapeutic strategy.

[Synchronous well differentiated ileal neuroendocrine tumour and colonic adenocarcinoma. A case report and a review of the literature]

Synchronous colonic adenocarcinoma and well-differentiated ileal neuroendocrine tumour are infrequent and are usually incidental findings on autopsies or resected surgical specimens. Only rarely are they detected on colonoscopies or during surgery. We present a case of a synchronous caecal adenocarcinoma and well-differentiated ileal neuroendocrine tumour, undetected during colonoscopy, with carcinoid metastasis in one regional lymph node not associated with adenocarcinoma metastasis. A review of the literature shows that the association of non-synchronous second primary malignancies in patients with gastrointestinal carcinoid tumours is reported in more than 50% of cases; however, synchronous tumours are found in only 1-8%. It would appear that well-differentiated ileal neuroendocrine tumour could be a predisposing factor for the development of a second malignancy.

Pancreatic accessory spleen. False positive with 99mTc-Octreotide

The case is presented on a patient with abdominal pain and suspicion of neuroendocrine tumor in the tail of the pancreas shown in the abdominal CT and MRI. Whole-body scintigraphy and abdominal SPECT/CT with ^99mTc-octreotide were performed that showed a nodular lesion partially on the posterior side of the pancreas tail. This nodule showed faint tracer uptake, and was reported as probable neuroendocrine tumor. Partial pancreatectomy and splenectomy were performed, and the histological study identified the lesion as an ectopic spleen. There are similar cases in the literature that match these findings, but this lesion is still frequently diagnosed after performing unnecessary surgery. When an asymptomatic intrapancreatic mass is detected, an accessory spleen should be considered and specific diagnostic techniques should be performed, such as labeled and denatured red blood cell SPECT/CT.