Diagnostic Management of Gastroenteropancreatic Neuroendocrine Neoplasms: Technique Optimization and Tips and Tricks for Radiologists.

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) comprise a heterogeneous group of neoplasms, which derive from cells of the diffuse neuroendocrine system that specializes in producing hormones and neuropeptides and arise in most cases sporadically and, to a lesser extent, in the context of complex genetic syndromes. Furthermore, they are primarily nonfunctioning, while, in the case of insulinomas, gastrinomas, glucagonomas, vipomas, and somatostatinomas, they produce hormones responsible for clinical syndromes. The GEP-NEN tumor grade and cell differentiation may result in different clinical behaviors and prognoses, with grade one (G1) and grade two (G2) neuroendocrine tumors showing a more favorable outcome than grade three (G3) NET and neuroendocrine carcinoma. Two critical issues should be considered in the NEN diagnostic workup: first, the need to identify the presence of the tumor, and, second, to define the primary site and evaluate regional and distant metastases. Indeed, the primary site, stage, grade, and function are prognostic factors that the radiologist should evaluate to guide prognosis and management. The correct diagnostic management of the patient includes a combination of morphological and functional evaluations. Concerning morphological evaluations, according to the consensus guidelines of the European Neuroendocrine Tumor Society (ENETS), computed tomography (CT) with a contrast medium is recommended. Contrast-enhanced magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), is usually indicated for use to evaluate the liver, pancreas, brain, and bones. Ultrasonography (US) is often helpful in the initial diagnosis of liver metastases, and contrast-enhanced ultrasound (CEUS) can solve problems in characterizing the liver, as this tool can guide the biopsy of liver lesions. In addition, intraoperative ultrasound is an effective tool during surgical procedures. Positron emission tomography (PET-CT) with FDG for nonfunctioning lesions and somatostatin analogs for functional lesions are very useful for identifying and evaluating metabolic receptors. The detection of heterogeneity in somatostatin receptor (SSTR) expression is also crucial for treatment decision making. In this narrative review, we have described the role of morphological and functional imaging tools in the assessment of GEP-NENs according to current major guidelines.

Spontaneously reversible adrenal nodules in primary diffuse large B-cell testicular lymphoma mimicking an extranodal involvement: A case report.

In the staging of cancer patients, transient and spontaneously reversible bilateral adrenal hypertrophy may mimic a secondary localization of the disease. We discuss the case of an 82-year-old male patient with suspected testicular neoplasia in which abdominal CT examination reveals the onset of a bilateral macronodular adrenal enlargement, suggesting the diagnostic hypothesis of primary testicular neoplasia with secondary adrenal localization. The subsequent 18FDG-PET/CT study showed hyper-metabolism of the testicular mass, while the adrenal glands, surprisingly, did not show increased uptake of the radiotracer. After right orchifunicolectomy, primary testicular diffuse large B-cell lymphoma was diagnosed. The subsequent staging PET/CT study with iodine contrast medium, three months after the first CT examination, showed spontaneous complete regression of the adrenal hypertrophy without any use of drug therapy. The differential diagnosis of this finding considered the lack of hypermetabolism and the densitometric characteristics of the adrenal glands, the absence of possible pharmacological interactions throughout the time of the diagnostic procedures, and the available clinical-laboratory data. By excluding the main causes of adrenal hypertrophy, the most likely diagnostic hypothesis was transient adrenal hypertrophy due to stress induced by testicular lymphoma, meaning by stress a disturbance not only emotional but also an alteration of organic homeostasis. Our case suggests that the analysis of adrenal lesions appeared in cancer patients should take into account non-metastatic conditions that must be studied with a multimodal approach and with serial investigations.

Diagnostic Contribution of Contrast-Enhanced CT as Compared with Unenhanced Low-Dose CT in PET/CT Staging and Treatment Response Assessment of 18F-FDG-Avid Lymphomas: A Prospective Study.

The aim of this study was to assess the added diagnostic value of contrast-enhanced CT (CECT) as compared with unenhanced CT (UECT) in PET/CT staging and treatment response assessment of 18F-FDG-avid lymphomas. Methods: 170 PET/UECT scans followed by CECT scans were prospectively performed for staging (n = 85) and for treatment response assessment (n = 85) of 18F-FDG-avid lymphomas, during a single session using an integrated 64-slice PET/CT scanner. CECT and UECT images were evaluated separately by 2 radiologists, whereas PET images were evaluated by 2 nuclear physicians. Nodal and extranodal UECT and CECT findings were classified according to the Lugano criteria and were successively compared with PET/CT results, considered the gold standard. In the analyzed groups, the agreement rate with the disease status determined via PET was calculated separately for UECT and CECT using the McNemar test on paired data. The added value of the contrast medium was shown by the agreement between the PET and CECT results and the lack of agreement between UECT and PET. Results: CECT enabled the identification of additional extranodal lesions (hepatic, muscular, and gastric) in only 3 staging group cases (3.5%), indicating different stages as compared with UECT, whereas there was absolute agreement between CECT and UECT in terms of treatment response assessment. The added diagnostic value of CECT was lower than the established threshold for clinical relevance (15%). The McNemar test indicated no statistical significance in either group. The incidental findings detected by CECT but not UECT were important for clinical management but not sufficient to alter lymphoma treatment strategy. Conclusion: According to our results, it might be possible to exclude CECT examination of 18F-FDG-avid lymphoma from staging and treatment response assessment, with the consequent advantages of reducing radiation exposure and potential contrast-related risks.

Functional Magnetic Resonance Imaging in the Olfactory Perception of the Same Stimuli.

BACKGROUND: Data in the literature report that a number of studies have attempted to identify the exact location of the cortical olfaction representation, searching for evidence suggesting that sniffing odors can initiate a primary activation of the piriform cortex and the insula. Nowadays, due to the SARS-CoV-2 (COVID-19) outbreak, the functional study of the olfactory system could offer a better understanding of the physiopathology of olfactory perception, elucidating better the possible site(s) of damage induced by the COVID-19 infection. The aim of this paper was to evaluate brain maps generated from functional Magnetic Resonance Imaging (fMRI) data, collected from healthy individuals in response to the same olfactory stimulus. METHODS: A total of 45 healthy volunteers, without history and/or no clinical signs of sinonasal disease and without history and/or presence of olfactory dysfunction underwent fMRI assessment. Subjects were presented with the same odorous stimuli at specific intervals. fMRI generated brain maps were used in the identification of different cortical areas, involved in the stimuli perception. RESULTS: The fMRI brain maps showed that odorous stimuli activate primarily the left anterior insula (in 35/45 cases or 77.8%). Other activated areas include: the low temporal gyri, the middle and superior temporal gyri, the frontal and piriform cortex, the anterior cingulate gyrus, the parahippocampal gyrus, the temporopolar area, the para-insular area, the subcentral area, the supramarginal gyrus, the occipital cortex and the cerebellum. CONCLUSIONS: fMRI resulted as a safe and reliable means to study the perception of olfaction in the cortex. The data of this study suggest that the anterior insula is the main stimulated area when olfactory stimuli are present. This area is always activated, despite the hand and nostril dominance.

Pitfalls in the embolisation of a thyrocervical trunk bleeding: a case report.

INTRODUCTION: An intrathoracic bleeding from the thyrocervical branch is not common in blunt trauma, but an interventional radiologist should be aware of the risks in order to prevent complications. CASE PRESENTATION: A 30-year-old male presented with a right pneumo-haemothorax due to active bleeding revealed at contrast-enhanced CT, as a consequence of a fall occurred in the previous week. The patient was treated with endovascular embolisation in an angiographic room with coils placement, since the right thyrocervical artery was found to be supplying the pneumo-haemothorax. A radiculo-medullary branch rose from the thyrocervical trunk, impeding the proximal embolization with microparticles and needing selective isolation of the bleeding artery with the catheter to avoid spinal cord injuries. The treatment had a successful result and the following CT control showed signs of recovering, without any complication. CONCLUSION: Our paper presents a rare contingency, warning the operator to bear in mind the presence of arteries feeding the spinal cord. This crucial detail precludes the use of microparticles embolisation to prevent neurologic sequelae, whereas the use of endovascular coils for embolization should be mandatory. Moreover, this case reminds that the post-traumatic bleeding deriving from a cervical trauma may also occur later.

Neck paraganglioma and follicular lymphoma: a case report.

BACKGROUND: Paragangliomas and pheochromocytomas are sympathetic or parasympathetic tumors derived from the paraganglia and the adrenal medulla, respectively. Paragangliomas and pheochromocytomas can be sporadic or familial, the latter frequently being multifocal and possibly due to succinate dehydrogenase complex genes mutations. In addition, 12% of sporadic paragangliomas are related to covered succinate dehydrogenase complex mutations. The importance of identifying succinate dehydrogenase complex mutations is related to the risk for these patients of developing multiple tumors, including non-endocrine ones, showing an aggressive clinical presentation. CASE PRESENTATION: We report the case of a 45-year-old Caucasian man with an indolent mass in his neck. Ultrasound of his neck, magnetic resonance imaging, and 1,4,7,10-tetraazacyclododecane-N(I),N(II),N(III),N(IIII)-tetraacetic acid(D)-Phe(1)-thy(3)-octreotide (68Ga-DOTATOC) positron emission tomography-computed tomography and endocrine work-up were consistent with a carotid body paraganglioma with concomitant nodal enlargement in several body regions, which turned out to be a follicular lymphoma at histology. He was found to carry a germline Succinate dehydrogenase subunit B gene (SDHB) mutation. CONCLUSION: It is crucial to look for a second malignancy in the case of a paraganglioma demonstrating succinate dehydrogenase complex germline mutations.