Assessment of MR Imaging and CT in Differentiating Hereditary and Nonhereditary Paragangliomas.

BACKGROUND AND PURPOSE: Head and neck paragangliomas have been reported to be associated with mutations of the succinate dehydrogenase enzyme family. The aim of this study was to assess whether radiologic features could differentiate between paragangliomas in the head and neck positive and negative for the succinate dehydrogenase mutation. MATERIALS AND METHODS: This single-center retrospective review from January 2015 to January 2020 included 40 patients with 48 paragangliomas (30 tumors positive for succinate dehydrogenase mutation in 23 patients and 18 tumors negative for the succinate dehydrogenase mutation in 17 patients). ADC values and tumor characteristics on CT and MR imaging were evaluated by 2 radiologists. Differences between the 2 cohorts in the diagnostic performance of ADC and normalized ADC (ratio to ADC in the medulla oblongata) values were evaluated using the independent samples t test. P < .05 was considered significant. RESULTS: ADCmean (1.07 [SD, 0.25]/1.04 [SD, 0.12] versus 1.31 [SD, 0.16]/1.30 [SD, 0.20]× 10-3 mm2/s by radiologists 1 and 2; P < .001), ADCmaximum (1.49 [SD, 0.27]/1.49 [SD, 0.20] versus 2.01 [SD, 0.16]/1.87 [SD, 0.20] × 10-3 mm2/s; P < .001), normalized ADCmean (1.40 [SD, 0.33]/1.37 [SD, 0.16] versus 1.73 [SD, 0.22]/1.74 [SD, 0.27]; P < .001), and normalized ADCmaximum (1.95 [SD, 0.37]/1.97 [SD, 0.27] versus 2.64 [SD, 0.22]/2.48 [SD, 0.28]; P < .001) were significantly lower in succinate dehydrogenase mutation-positive than mutation-negative tumors. ADCminimum, normalized ADCminimum, and tumor characteristics were not statistically significant. CONCLUSIONS: ADC is a promising imaging biomarker that can help differentiate succinate dehydrogenase mutation-positive from mutation-negative paragangliomas in the head and neck.

Carotid Body Tumor - radiological imaging and genetic assessment.

Carotid Body Tumor i.e. Paraganglioma is a challenging entity from the point of multidisciplinary diagnosis. The main treatment option i.e. surgery yields intraoperative risk,related to cranial nerve palsy and vascular morbidity.Bifurcation of Common Carotid Artery especially at the Carotid Body is the place where Head and Neck Paraganglioma is most frequently seen i.e. 60% of incidence [19]. Indeed, the knowledge of genetic germline SDH mutations, which cause deregulation of hypoxia-induced factors yields better understanding of the tumor nature. It is recommended to conduct selective neck dissection in regions IIA, IIB, III to exlude malignant transformation and metastasis, due to malignant potential of Carotid Body Tumors, especially in case of SDHB mutation. SDHD mutation is the main cause of hereditary HNPGLs. Computed tomography (CT), magnetic resonance imaging (MRI) and angiography yield thorough assessment of paraganglioma extension. In large size tumors, embolization of supplying artery under guidance of angiography may be considered. In case of Carotid Body Tumor, differential diagnosis should include: carotid artery aneurysm, lymphadenopathy, Schwannoma of the hypoglossal nerve or acessory thyroid gland.

A probabilistic assessment of the diagnosis of paraganglioma/pheochromocytoma based on clinical criteria and biochemical/imaging findings.

UNLABELLED: Paragangliomas (PGL) and pheochromocytomas (P) are rare neural-crest-derived neoplasms. Very recently guidelines on diagnosis and treatment of PGL/P have been presented by the US Endocrine Society. In the following overview we assessed the implementation of these guidelines with probabilistic reasoning (calculating with Fagan nomograms the post-test probability of PGL/P for a given pre-test probability). CONCLUSION: Biochemical evaluation of PGL/P showed excellent diagnostic characteristics with post-test probabilities that are very different from the pre-test probabilities, thus a positive biochemical test is usually indicative of disease whereas a negative one usually rules out disease. The post-test probabilities of anatomical and functional imaging modalities (i.e. in nuclear medicine) were different from the pre-test probabilities but to a lesser degree than the biochemical tests; furthermore in biochemically-proven PGL/P a negative imaging modality is not useful, while a positive one may indicate only one of multiple foci of metastatic/extra-adrenal disease. Thus, regarding imaging modalities, they should be combined in order to get the most of their characteristics for the localization of PGL/P.

Emergency catheter probe endoscopic sonography (CP-EUS): an effective procedure in the assessment of a bleeding gangliocytic paraganglioma.

Catheter probe endoscopic sonography is a relatively rapid and safe procedure, carried out during standard endoscopy, capable of distinguishing solid from cystic lesions and vascular from avascular masses. Herein we discuss the role of catheter probe endoscopic sonography in the emergency assessment of a patient with recent and severe bleeding from an ulcerated polyp, arising from the papilla. During the endoscopy, catheter probe endoscopic sonography showed the solid and submucosal nature of the lesion, suggesting its localised and benign nature and, most importantly, demonstrating the high risk of rebleeding from vascular structures communicating with the ulcer. Because of this finding three metallic endoclips were positioned. The lesion was not removed endoscopically because of its difficult position and the high risk of haemorrhage. The mass, removed through a duodenotomy, was shown to be a gangliocytic paraganglioma, an uncommon tumour, frequently resulting in surgery because of abdominal pain and gastrointestinal bleeding.

Gangliocytic paraganglioma of the bronchus: a case report with follow-up and ultrastructural assessment.

We report a case of gangliocytic paraganglioma of bronchus. A 54-year-old woman underwent bronchoscopy following two episodes of right lower lobe pneumonia over the previous 5 months with unresolved chest radiographic changes. A computerized tomographic scan showed a right lower lobe endobronchial lesion, and at bronchoscopy there was a mass partly occluding the lumen of the bronchus. The biopsy and subsequent bronchoscopic resection showed a tumor with morphologic, immunohistochemical, and ultrastructural features of paragangliomatous, gangliocytic, and Schwann cell differentiation consistent with a gangliocytic paraganglioma. The lesion was treated conservatively with bronchoscopic resection and laser therapy. Histopathologic examination of recurrent tumor at 6 months showed features consistent with paraganglioma. Ten months after initial diagnosis, there was no bronchoscopic evidence of residual tumor. The occurrence of gangliocytic paraganglioma in diverse sites gives cause for the reappraisal of the histogenesis of this fascinating lesion. The variable morphology of this lesion may be an expression of the potential for divergent differentiation of a pluripotent stem cell.

Radiographic evaluation and assessment of paragangliomas.

Radiographic imaging plays an important role in the diagnosis and treatment of paragangliomas. Diagnosis and treatment should be performed as a team effort, with all the involved disciplines working together to provide the best possible individualized work-up and treatment plan for the patient.

Cost-effectiveness analysis of somatostatin receptor scintigraphy.

UNLABELLED: We analyzed the results of conventional imaging and somatostatin receptor scintigraphy in 150 patients with neuroendocrine tumors. METHODS: The outcomes of combinations of imaging modalities were compared in terms of tumor localization, effect on patient management and financial costs. RESULTS: In patients with carcinoids, a combination of somatostatin receptor scintigraphy, chest radiograph and ultrasound of the upper abdomen had a high sensitivity for tumor localization, and detected lesions in patients in whom no tumor was found with conventional imaging, justifying the greater cost. In patients with medullary thyroid carcinoma, somatostatin receptor scintigraphy adds little to the information obtained with conventional imaging and therefore should not be used as a screening method. In patients with paraganglioma, CT scanning of the region where a paraganglioma is suspected, followed by somatostatin receptor scintigraphy to detect multicentricity has the best cost effectiveness ratio. In patients with gastrinomas, the combination of somatostatin receptor scintigraphy and CT scanning of the upper abdomen had the highest sensitivity. The relatively high cost of this process is outweighed by its demonstrating a resectable tumor. In patients with insulinomas, the highest yield against the lowest cost is obtained if somatostatin receptor scintigraphy is only performed if CT scanning fails to demonstrate the tumor. CONCLUSIONS: Somatostatin receptor scintigraphy should be performed in patients with small-cell lung carcinoma because it can lead to a change of stage and may demonstrate otherwise undetected brain metastases. The cost increase is outweighed by the omission of unnecessary treatment for some of the patients and by the possibility of irradiating brain metastases at an early stage, which may lead to a better quality of life.