From microbiota toward gastro-enteropancreatic neuroendocrine neoplasms: Are we on the highway to hell?

Gut microbiota is represented by different microorganisms that colonize the intestinal tract, mostly the large intestine, such as bacteria, fungi, archaea and viruses. The gut microbial balance has a key role in several functions. It modulates the host’s metabolism, maintains the gut barrier integrity, participates in the xenobiotics and drug metabolism, and acts as protection against gastro-intestinal pathogens through the host’s immune system modulation. The impaired gut microbiota, called dysbiosis, may be the result of an imbalance in this equilibrium and is linked with different diseases, including cancer. While most of the studies have focused on the association between microbiota and gastrointestinal adenocarcinomas, very little is known about gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs). In this review, we provide an overview concerning the complex interplay between gut microbiota and GEP NENs, focusing on the potential role in tumorigenesis and progression in these tumors.

     

The natural history of incidentally discovered adrenocortical adenomas: a retrospective evaluation

Adrenal adenoma is the most frequent lesion among adrenal incidentalomas. The present retrospective study was undertaken to investigate medium-term evolution of supposed or ascertained adrenocortical adenomas in a group of 53 subjects (16 males and 37 females, aged 31-83 yr), with bilateral (no.=8) or monolateral (no.=45) incidentally discovered adrenal masses (size 10-50 mm, median 25 mm), who were followed-up for 6-78 months (median 24 months). Diagnosis of adenoma was based on size and morphovolumetric aspect of the lesion at computed tomography (CT), scintigraphic pattern using NP59 as a tracer, and it was histologically confirmed in 7 patients. After an extensive hormonal investigation including morning (no.=53) and midnight (no.=28) serum cortisol, plasma ACTH (no.=50), serum DHEAS (no.=51), daily urinary free cortisol excretion (no.=52), post-dexamethasone (1 mg) cortisol (no.=42) and ACTH stimulation test for 17-hydroxyprogesterone (17-OHP) response (no.=48) at the time of diagnosis, patients were periodically re-evaluated for hormonal function and radiological aspect of the lesion(s) by CT. Seven patients underwent surgery 6-42 months after incidentaloma demonstration, with histological diagnosis of adrenal adenoma. During follow-up an increase in the size of the lesion was demonstrated in 22 patients (41.5%); the increase was greater than 10 mm in 8 cases. In 3 patients with unilateral mass, a contralateral lesion appeared 10-52 months after first demonstration. Six patients (11.3%) showed reduction or disappearance of the lesions. On the basis of the hormonal evaluation 3 patients were considered to have subclinical Cushing's syndrome and 10 patients exhibited 17-OHP hyperresponse to ACTH test consistent with partial 21 -hydroxylase deficiency. A significant difference in the size of the lesions was observed between patients with or without 17-OHP hyperresponse to ACTH test (31.1 1.9 vs 24.1 +/- 1.2 mm; p<0.01). No significant changes in the hormonal parameters were observed in the patients, when retested. In conclusion, although none of the patients of the present series exhibited evolution to hypersecretion or to aberrant growth, in more than 40% of patients an increase in the size of the mass was observed, even after a long period of "quiescence". This suggests that a radiological re-evaluation of lesions should be periodically undertaken.     

Laparoscopic bilateral simultaneous adrenalectomy: results of 11 operations

BACKGROUND: This study was undertaken to evaluate the outcomes of the simultaneous bilateral laparoscopic adrenalectomy. MATERIALS AND METHODS: This was a retrospective study, including 11 patients with bilateral adrenal lesions, affected by Cushing's syndrome (n=2), Cushing's disease (n=6), pheochromocytoma (n=2), and 1 adrenocorticotrophin-hormone-dependent hypercortisolism of unknown origin. RESULTS: Elevan bilateral adrenalectomies were carried out by the laparoscopic approach with no conversions. The operations were performed in 7 cases by the lateral transperitoneal adrenalectomy (LTLA), in 3 by the posterior approach (PRA), and in 1 by the combined approach. The mean size of the masses was 5 cm. (range, 4-13). The average operating time was 245 minutes for LTLA and 218 minutes for PRA (P<0.05). The estimated mean blood loss was 87+/-36 mL (range, 20-150). No patients required transfusions. The mean hospital stay was 5+/-1.8 days (range, 4-7). The mean follow-up was 34 months (range, 2-96). CONCLUSIONS: Our study confirms that the bilateral adrenalectomy by the minimally invasive technique is safe and effective, affording acceptable blood loss and morbidity with a short hospital stay.     

Spontaneous recovery of bone mass after cure of endogenous hypercortisolism

Patients with Cushing??s syndrome (CS) develop osteopenia-osteoporosis. The present study evaluates the recovery of bone mass within 2?years after remission of hypercortisolism and in long term follow up, an issue rarely addressed. Twenty patients (6M, 14F, 3 post-menopausal, 15?C64?years old), 15 with Cushing??s disease, 2 with ectopic ACTH syndrome, 3 with ACTH-independent CS were studied. BMD, T and Z scores at lumbar spine and proximal femur were assessed by dual-energy X-ray absorptiometry before and 7?C33?months after treatment of hypercortisolism. Five patients were treated with bisphosphonates. Four patients had hypogonadism and 4 GH-deficiency. At baseline all patients showed osteopenia/osteoporosis and the spine appeared more damaged than the femur; femur BMD was positively related with body mass index (BMI). No correlations were observed between spine and femur bone parameters and duration of disease or severity of hypercortisolism. Bone parameters did not differ in patients with or without GH or other pituitary deficiencies. After cure of hypercortisolism a significant improvement in spine BMD, Z and T scores and in femur Z and T scores was observed with normalization in 3 patients; there was no significant difference in percent improvement between femur and spine. The increase in bone parameters at spine and femur was independent from values at baseline. The percent increase in spine T and Z scores was positively related with time elapsed since cure. Bisphosphonates did not influence the recovery of bone mineralization. In long term follow up, after a median period of 7?years a further improvement in bone density was observed in 100% of patients at spine and in 9/11 at femur, although 8/11 patients still had femoral and/or vertebral T score in the range of osteopenia/osteoporosis. Spontaneous improvement of osteoporosis after cure of hypercortisolism occurs both at spine and femur, is independent from basal conditions and not affected by bisphosphonates. The improvement at spine depends on time since cure.     

Effectiveness of low‐dose pasireotide in a patient with Cushing's disease: antiproliferative effect and predictivity of a short pasireotide suppression test

This case shows efficacy of low‐dose pasireotide in biochemical and clinical control of severe hypercortisolism and in tumor volume reduction in a patient with an ACTH‐secreting macroadenoma. The drug may be an option for long‐term treatment in some patients where control of tumor mass is an important clinical endpoint.     

Outcomes of laparoscopic adrenalectomy. Clinical experience with 68 patients

The aim of this study was to analyze feasibility and outcomes of laparoscopic adrenalectomy (LA). Pathology, size and bilateral site of lesions were considered. Between December 1998 and May 2007 in our institution a total of 68 patients of mean age of 53 years underwent unilateral (n=57) or bilateral (n=11) LA. Adrenal masses averaged 5.4cm in size (range 1.2-13cm) and 56.7g in weight (range 10-265) including 71 benign and 8 malignant lesions. A total of 79 adrenal glands were resected, 44 right sided and 35 left sided. Removal was complete in 77 cases and partial (sparing adrenalectomy) in 1 patient affected by bilateral pheochomocytoma. Three left adrenalectomies for pheochromocytoma were robot-assisted. The transperitoneal lateral approach was preferred and the posterior retroperitoneal approach was adopted in 5 patients. The mean duration of surgery for each LA was 138+/-90min and 3.8 trocar were used on average (range 3-6). Conversion was needed in 3 cases owing to difficult dissection of large masses. Estimated mean blood loss for each LA was 95+/-30ml and it was greater for bilateral LA. Mortality was nil and morbidity was 5.8%. The average length of hospital stay (LOS) in surgical unit was 4+/-2.4 days (range 2-8). Patients affected by hormone secreting or bilateral lesions, by unilateral or bilateral pheochromocytoma and by bilateral Cushing's disease were transferred to the endocrinological ward so that their overall hospital stay was prolonged to 9+/-2.8 days on average (range 7-17). Mean duration of follow-up of patients was 38 months (range 2-100) and demonstrated acceptable endocrine results. Three primary cortical carcinomas were discovered as chance findings on histologic examination. While long-term results after LA for cortical carcinomas were poor and LA is not recommended in such cases, long-term results after LA for adrenal metastases were encouraging.     

Use of radioguided surgery with [111In]-pentetreotide in the management of an ACTH-secreting bronchial carcinoid causing ectopic Cushing's syndrome

Intraoperative [111In]-pentetreotide scintigraphy with a hand-held gamma detector probe has recently been proposed to increase the intraoperative detection rate of small neuroendocrine tumors and their metastases. We report a case of a 28-yr-old woman with ectopic Cushing's syndrome due to an ACTH-secreting bronchial carcinoid, in whom the use of radioguided surgery improved disease management. At presentation, radiolabeled pentetreotide scintigraphy was the only procedure able to detect the ectopic source of ACTH. After radiologic confirmation, the patient underwent removal of a bronchial carcinoid, with disease persistence. After surgery, pentetreotide scintigraphy showed pathologic uptake in the mediastinum not previously detected at surgery and only subsequently confirmed by radiologic studies. Despite a second thoracic exploration, hormonal, scintigraphic, and radiological evidence of residual disease persisted. Radioguided surgery was then performed using a hand-held gamma probe 48 h after iv administration of a tracer dose of radiolabeled [111In-DTPA-D-Phe1]-pentetreotide, which permitted detection and removal of multiple residual mediastinal lymph node metastases. Clinical and radiologic cure, with no evidence of tracer uptake at pentetreotide scintigraphy, was subsequently observed. The use of an intraoperative gamma counter appears a promising procedure in the management of metastatic ACTH-secreting bronchial carcinoids.     

Management of occult adrenocorticotropin-secreting bronchial carcinoids: limits of endocrine testing and imaging techniques

The differential diagnosis and the identification of the source of ACTH in occult ectopic Cushing's syndrome due to a bronchial carcinoid still represents a challenge for the endocrinologist. We report our experience in six patients with occult bronchial carcinoid in whom extensive hormonal, imaging, and scintigraphic evaluation was performed. All patients presented with hypercortisolism associated with high plasma ACTH values. The CRH test and high dose dexamethasone suppression test suggested an ectopic source of ACTH in three of six patients. During bilateral inferior petrosal sinus sampling, none of the patients showed a central to peripheral ACTH gradient. At the time of diagnosis, none of the patients had radiological evidence of the ectopic source of ACTH, whereas pentetreotide scintigraphy identified the lesion in two of four patients. Finally, a chest computed tomography scan revealed the presence of a bronchial lesion in all patients, and pentetreotide scintigraphy identified four of six lesions. In all patients a bronchial carcinoid was found and removed. In one patient with scintigraphic evidence of residual disease after two operations, radioguided surgery, using a hand-held gamma probe after iv administration of radiolabeled pentetreotide, was performed; this allowed detection and removal of residual multiple mediastinal lymph node metastases. In conclusion, our data show that there is not a single endocrine test or imaging procedure accurate enough to diagnose and localize occult ectopic ACTH-secreting bronchial carcinoids. Radioguided surgery appears to be promising in the presence of multiple tumor foci and previous incomplete removal of the tumor.