18F-FDG PET/CT in the Hyperparathyroidism-Jaw-Tumor Syndrome.

ABSTRACT: Hyperparathyroidism-jaw-tumor syndrome (HPT-JTS) is a rare autosomal dominant disorder. A typical manifestation of HPT-JTS is the association of jaw-ossifying fibroma with primary hyperparathyroidism. Due to its rarity and diversity in its manifestations, it is a challenging diagnosis. A 33-year-old woman was referred due to painful swelling of the right maxilla suggestive of malignancy. The clinical presentations were not conclusive until she underwent F18-fluorodeoxyglucose positron emission tomography/computed tomography (F18-FDG PET/CT). F18-FDG PET/CT proved to be a useful tool to assist the clinicians in visualizing the "bigger picture" and, therefore all manifestation as pieces of "one puzzle."

Differences in intraosseous and extraosseous post-chemotherapy regression of Ewing sarcomas and their influence on prognosis.

BACKGROUND: In Ewing sarcomas (ES), histological response to polychemotherapy is the main prognostic factor. We aimed at evaluating the histological response separately for the extraosseous and intraosseous tumor compartment as well as its prognostic influence. METHODS: Thirty-one patients with ES and marked soft tissue expansion, treated at our department between January 2006 and December 2015, were retrospectively included. Data was taken from medical records. Original histologic specimens of the resected tumors were re-evaluated separately for intra- and extraosseous tumor regression according to Salzer-Kuntschik regression grading. Multivariate survival analysis with stepwise backward variable selection was calculated to determine the impact of extraosseous and intraosseous regression on prognosis. RESULTS: All patients had received chemotherapy, 15 (48.4%) had been administered preoperative radiotherapy. Extraosseous tumor regression was significantly worse than intraosseous regression (Wilcoxon signed-rank test, p = 0.018). While neither intraosseous nor extraosseous tumor regression had an impact on overall survival, extraosseous complete remission had a beneficial impact on event-free-survival in the multivariate analysis (Cox-regression; hazard ratio: 0.148, 95% confidence interval 0.031-0.707, p = 0.017). CONCLUSIONS: On average, regression of ES seems to be worse in the extraosseous tumor compartment following preoperative chemotherapy. Moreover, extraosseous tumor regression may have a stronger prognostic influence on event-free survival than intraosseous regression.

EZH2 is upregulated in the proliferation centers of CLL/SLL lymph nodes.

Lymph node involvement of chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) is characterised by the diffuse infiltration of small neoplastic lymphocytes, which is accompanied by the presence of proliferation centres (PCs) comprising prolymphocytes and paraimmunoblasts. There is increasing evidence of accumulation of various molecular alterations in the tumour cells of PCs, which may explain why extended PCs are related to a less favourable prognosis. To further characterize PCs, we compared the expression level of EZH2 protein, the overexpression of which has recently been recognized as poor prognostic factor in CLL/SLL, in the PCs and the intervening small cell areas in lymph nodes of 15 patients with CLL/SLL. We also investigated the mutational profile of EZH2 and the expression of its upstream regulators c-Myc, E2F1, pRB and miR-26a. Our results showed a significantly increased expression of EZH2 in the PCs. No EZH2 mutations were detected, however, overexpression of c-Myc, E2F1 and pRb proteins as well as reduced expression of the tumor suppressor miR-26a were demonstrated in the PCs. In summary our findings indicate that EZH2 pathway is significantly upregulated in the PCs of CLL/SLL lymph nodes, providing further evidence for the distinguished biological features of the PCs.

Rarity among benign gastric tumors: Plexiform fibromyxoma - Report of two cases.

Plexiform fibromyxoma is a very rare mesenchymal tumor of the stomach, found almost exclusively in the antrum/pylorus region. The most common presenting symptoms are anemia, hematemesis, nausea and unintentional weight loss, without sex or age predilection. We describe here two cases of plexiform fibromyxoma, involving a 16-year-old female and a 34-year-old male. Both patients underwent complete resection (R0) by distal gastrectomy and retrocolic gastrojejunostomy (according to Billroth 2); for both, the postoperative course was uneventful. Histology showed multiple intramural and subserosal nodules with characteristic plexiform growth, featuring bland spindle cells situated in an abundant myxoid stroma with low mitotic activity. Immunohistochemistry showed α-smooth muscle actin-positive spindle cells, focal positivity for CD10, and negative staining for KIT, DOG1, CD34, S100, ß-catenin, STAT-6 and anaplastic lymphoma kinase. One of the cases showed focal positivity for h-caldesmon and desmin. Upon follow-up, no sign of disease was found. In the differential diagnosis of plexiform fibromyxoma, it is important to exclude the more common gastrointestinal stromal tumors as they have greater potential for aggressive behavior. Other lesions, like neuronal and vascular tumors, inflammatory fibroid polyps, abdominal desmoid-type fibromatosis, solitary fibrous tumors and smooth muscle tumors, must also be excluded.

Role of Next-Generation Sequencing as a Diagnostic Tool for the Evaluation of Bone and Soft-Tissue Tumors.

Bone and soft-tissue tumors are in general rare. Diagnosing these tumors is challenging based on the significant number of different tumor entities, the rareness of these tumors, and the considerable morphological heterogeneity which can be found within a single tumor entity. Considering that more than half of the described soft-tissue tumors and approximately 25% of the bone tumors harbor recurrent genetic alterations, the use of auxiliary molecular examinations should be strongly considered. Molecular analyses are important to confirm the diagnosis, to guide treatment, to provide information about prognosis, and to allow patient recruitment for basket trials based on the molecular signature of a tumor. In addition, novel molecular alterations detected by next-generation sequencing (NGS) obtain further insights into the pathogenesis of these rare tumors and allow a more detailed genetic classification. Based on our single-center results of NGS using the Ion AmpliSeq Cancer Hotspot Panel v2 and the Ion AmpliSeq Comprehensive Cancer Panel (Thermo Fisher Scientific) for mutational analyses as well as the Archer FusionPlex Sarcoma Kit (ArcherDX, Inc) to detect gene fusions in 26 genes since early 2016, we have experienced NGS as a very sensitive method to detect genetic alterations. In our experience, the use of the Archer FusionPlex Sarcoma Kit is superior to fluorescent in situ hybridization as an auxiliary tool in the routine workup of soft-tissue and bone tumors.

Quantitative miR analysis in chronic lymphocytic leukaemia/small lymphocytic lymphoma - proliferation centres are characterized by high miR-92a and miR-155 and low miR-150 expression.

Proliferation centres (PCs) are histological hallmarks of lymph nodes in chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL). Chromosomal abnormalities have already been described to accumulate preferably in the PCs as opposed to the intervening small cell areas. To further characterize the pathogenic role of PCs, the expression levels of 17 selected miRs known to be involved in the development of CLL/SLL were compared in the PCs and the intervening small cell areas in lymph nodes of 15 patients with CLL/SLL. The miR expression levels were also compared to the cytogenetic alterations defined by FISH analysis. Our results show that two known oncomiRs, miR-155 and -92a were upregulated and the tumour suppressor miR-150 was downregulated in the PCs. Low expression of miR-150 was also associated with loss of 11q. In summary we found significantly higher expression of oncomiRs and lower expression of a tumour suppressor miR in PCs of CLL/SLL lymph nodes, which support the hypothesis that the PCs may drive the disease and play a role in progression.

1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene induces substantial hyperplasia in fibrotic mouse liver.

The proliferative response of hepatocytes in vivo can be induced by two mechanisms: severe damage to hepatic tissue results in regenerative growth and so-called primary hepatocyte mitogens can initiate liver cell proliferation without preceding loss of parenchyma. The regulation of the two responses is quite different. The decreased regenerative response of cirrhotic/fibrotic liver is well known, and is a severe obstacle to surgery of the diseased liver. In the present experiments we investigated the efficiency of a primary hepatocyte mitogen 1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOB) on two different liver cirrhosis/fibrosis models in mice induced by chronic administration of CCl(4) and thioacetamide respectively. BrdU incorporation and cyclin A expression established clearly that there is a reduced but still powerful mitogenic response of the fibrotic livers. Therefore, primary hepatocyte mitogens appear to be suitable to be used to rescue the regenerative response of cirrhotic livers.

The primary mitogen (TCPOBOP)-induced hepatocyte proliferation is resistant to transforming growth factor- ß-1 inhibition.

BACKGROUND: Transforming growth factor (TGF)-ß-1 is a very efficient inhibitor of hepatocyte proliferation in various in vivo and in vitro experimental systems. However, there are no data on whether it can influence the mitogenic response induced by primary hepatocyte mitogens. AIMS: In this study, we compared the proliferative response in the liver between wild-type and transgenic mice, overexpressing active TGF-ß-1 in their liver following the treatment by a primary hepatocyte mitogen TCPOBOP (1,4-bis[2-(3,5-dichloropyridyloxy)]benzene). METHODS: The proliferative response was characterized by the immunohistochemical examination of pulse and cumulative bromodeoxyuridine labelling and by quantitative real-time polymerase chain reaction analysis of cell cycle-related genes. RESULTS: Neither of the applied techniques revealed significant differences between the two groups of mice; furthermore, we observed the upregulation of TGF-ß-1 expression following the mitogenic treatment. CONCLUSIONS: TGF-ß-1 does not inhibit the primary mitogen-induced proliferative response of the hepatocytes. This observation may provide an explanation for the divergent consequences of hepatic proliferations induced by partial hepatectomy or primary mitogenic treatment.