Search

Paragangliomas and pheochromocytomas are rare neuroendocrine tumors, carrying a germ-line mutation in 40% patients. Sclerosis is a rare histological feature in these tumors. We investigated the possible correlations between histological findings, first sclerosis, immunoreactivity for vesicular catecholamine transporters (VMAT1/VMAT2) and patients' genotype in a consecutive series of 57 tumors (30 paragangliomas and 27 pheochromocytomas) from 55 patients. The M-GAPP grading system, sclerosis (0–3 scale) and VMAT1/VMAT2 (0–6 scale) immunoreactivity scores were assessed. Germ-line mutations of Succinate Dehydrogenase genes, RET proto-oncogene and Von Hippel Lindau tumor suppressor gene were searched. A germ-line mutation was found in 25/55 (45.5%) patients, mainly with paraganglioma (N = 14/30, 46,66%). Significant (score ≥ 2) tumor sclerosis was found in 9 (16.1%) tumors, i.e., 7 paragangliomas and 2 pheochromocytomas, most of them (8/9) from patients with a germ-line mutation. M-GAPP score was higher in the mutation status (in 76% of patients involving the SDHx genes, in 12% the RET gene and in the remaining 12% the VHL gene) and in tumors with sclerosis (p < 0.05). Spearman's rank correlation showed a strong correlation of germ-line mutations with M-GAPP (p < 0.0001) and sclerosis (p = 0.0027) scores; a significant correlation was also found between sclerosis and M-GAPP scores (p = 0.029). VMAT1 expression was higher in paragangliomas than in pheochromocytomas (p = 0.0006), the highest scores being more frequent in mutation-bearing patients' tumors (p < 0.01). VMAT2 was highly expressed in all but two negative tumors. Sclerosis and VMAT1 expression were higher in paragangliomas than in pheochromocytomas; tumor sclerosis, M-GAPP and VMAT1 scores were associated to germ-line mutations. Sclerosis might represent a histological marker of tumor susceptibility, prompting to genetic investigations in paragangliomas. [ABSTRACT FROM AUTHOR]

Background: Swallow tail sign (STS) on MRI is presumed to be an imaging biomarker of nigrosome‐1, which may exhibit a similar role as positron emission tomography (PET), indicating dopaminergic degeneration. Purpose: To investigate whether an alteration of STS could serve as an alternative screening sign compared with PET in the diagnosis of early‐stage Parkinson's disease (esPD). Study Type: Prospective. Population: Thirty‐seven patients with esPD and 27 age‐ and sex‐matched healthy controls (HCs). Field Strength/Sequence: Quantitative susceptibility mapping images were collected on 3T MRI and [18F]9‐fluoropropyl‐(+)‐dihydrotetra‐benazine PET images were acquired using a 64 rings PET/CT scanner. Assessment: Alterations of STS and striatal uptake in each hemisphere were visually rated on a 0–2 points scale. Point 2: normal appearance of STS/normal striatal uptake; Point 1: partial loss of STS/uptake reduction confined to the putamen; Point 0: total loss of STS/uptake reduction extended to the caudate nucleus. The concordance rate of STS rating and ipsilateral striatal binding was calculated at the nuclei level. At the participant level, an evaluation rating was calculated by adding the STS ratings from both hemispheres to distinguish esPD from HCs. Statistical Tests: The intra‐ and interobserver agreement were tested using Cohen's kappa and the intraclass correlation coefficient. Hotelling's T‐squared test was used to compare the difference of rating points. Receiver operating characteristic analysis was performed to evaluate the diagnostic power. Results: The intra‐ and interobserver agreement for STS and striatal uptake rating was over 0.75. There was no significant difference of rating point distribution (P = 0.084). The concordance rate was 94.3% for the right side and 91.4% for the left. Using bilateral partial loss of STS as the threshold, the achieved sensitivity and specificity for discriminating esPD from HCs were 94.59% and 92.49%, respectively. Data Conclusion: STS alterations corresponded well with striatal uptake on PET in esPD, and our proposed evaluation scale of STS had satisfactory diagnostic performance in discriminating the disease. Level of Evidence: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]