NF1 gene analysis based on DHPLC

The high mutation rate at the NF1 locus results in a wide range of molecular abnormalities. The majority of these mutations are private and rare, generating elevated allelic diversity with a restricted number of recurrent mutations. In this study, we have assessed the efficacy of denaturing high-performance liquid chromatography (DHPLC), for detecting mutation in the NF1 gene. DHPLC is a fast and highly sensitive technique based on the detection of heteroduplexes in PCR products by ion pair reverse-phase HPLC under partially denaturing conditions. We established theoretical conditions for DHPLC analysis of all coding exons and splice junctions of the NF1 gene using the WAVEmaker software version 4.1.40 and screened for mutations a panel of 40 unrelated NF1 patients (25 sporadic and 15 familial), genetically uncharacterized. Disruptive mutations were identified in 29 individuals with an overall mutation detection rate of 72.5%. The mutations included eight deletions (exons 4b, 7, 10a, 14, 26, and 31), one insertion (exon 8), nine nonsense mutation (exons 10a, 13, 23.1, 27a, 29, 31, and 36), six missense mutations (exons 15, 16, 17, 24, and 31), four splice errors (exons 11, 14, 36, and 40) and a complex rearrangement within exon 16. Eighteen (62%) of the identified disruptive mutations are novel. Seven unclassified and three previously reported polymorphisms were also detected. None of the missense mutations identified in this study were found after screening of 150 controls. Our results suggest that DHPLC provides an accurate method for the rapid identification of NF1 mutations.     

Integrin b4 expression in peripheral-nerve tumors

The alpha 6 beta 4 integrin complex is expressed in epithelial, endothelial and nerve cells. We analyzed the immunohistochemical expression of the beta 4 subunit in normal peripheral nerves, in neurofibromas associated with type 1 neurofibromatosis and in sporadic neurofibrosarcomas. In normal peripheral nerves (4 samples), the beta 4 integrin was diffusely expressed at the level of the perinevrium and at the interface between axons and Schwann cells. In neurofibromas (6 cases), beta 4 was undetectable or markedly decreased relative to normal peripheral nerves. Neurofibrosarcomas (3 cases) were immunohistochemically negative for beta 4 expression. These observations suggest that a down-regulation of the alpha 6 beta 4 integrin is associated with the neoplastic progression of peripheral nerve tumors.     

Mammary Paget's disease with acantholytic features and without any detectable breast tumor

Paget's disease is usually associated with an underlying adenocarcinoma of the breast. The initial manifestation is an eczematous or psoriasiform lesion of the nipple, soon extending to the mammary areola and then to the surrounding skin. The histology of the lesions is characterized by the presence, within the epidermal layer, of the so-called Paget's cells, i.e. large cells with vesicular nucleus and clear cytoplasm. The authors report a recent case of Paget's disease of the breast in a 75-year-old woman, unusual both for clinical course and observed histology. As for the clinico-evolutive aspects, although in the case observed the initial skin lesions appeared 20 years before, the different diagnostic procedures repeatedly performed showed no evidence in this patient of an underlying adenocarcinoma. The histologic aspect, on the other hand, was peculiar since the typical characteristics of an acantholytic disease were evident. The presence of intraepidermal cleavages with lost, at times, of the normal contacts among the cells of the Malpighian layer has been described only once in Paget's disease. This fact caused some diagnostic difficulties: however, the typical finding of the Paget cells, their positivity to histochemical methods such as cytokeratin and acid phosphatase allowed the diagnosis. The authors, at last, evaluate the need of a surgical therapy in Paget's disease of the breast without an underlying adenocarcinoma.     

3D Non-Fluoroscopic Cryoablation of Right-Sided Accessory Pathways in Children: Monocentric Study and Literature Review

Background: Cryoablation of accessory pathways (APs) is effective and very safe in children, as previously reported by our group. The aim of this retrospective study was to evaluate the current efficacy of 3D non-fluoroscopic cryoablation of right sided APs in children, comparing results obtained with the Ensite Velocity^TM and the more recent Ensite Precision^TM 3D mapping systems. Methods and Results: From January 2016 to December 2019, 102 pediatric patients [mean age 12.5 ± 2.8, 62 males (61% of total cohort)] with right APs underwent 3D non-fluoroscopic transcatheter cryoablation at our Institution. Fifteen (14.7%) patients had previously undergone catheter ablation. Acute procedural success rate was 95.1% (n = 97). No significant differences were detected in acute success rates achieved with Ensite Velocity^TM or Ensite PrecisionTM systems nor between manifest (94%) and concealed APs (100%). No permanent complications occurred. During follow-up (428 ± 286 days, median 396 days [interquartile range 179-713]), 19 patients (19.6%) had recurrences. Recurrences were more frequent for parahissian/anterior APs compared to midseptal/posterior and lateral APs (p = 0.043). Recurrences were not related to the Ensite system used. A redo ablation procedure was attempted in 13 cases, 11 cryoablation and 2 radiofrequency ablations: the former was successful in 10 cases out of 11 (90.9%). Conclusion: 3D cryoablation of right-sided APs is associated with a very high acute success rate with limited use of fluoroscopy, resulting in great benefit to the children. Recurrence rates are not high and patients can be retreated with cryo-energy with higher success rates.     

The conserved PI3'K/PTEN/Akt signaling pathway regulates both cell size and survival in Drosophila

Akt (or PKB) is an oncogene involved in the regulation of cell survival. Akt is regulated by phosphatidylinositol 3-OH kinase (PI3'K) signaling and has shown to be hyperactivated through the loss of the PTEN tumor suppressor. In Drosophila, insulin signaling as studied using the Drosophila IRS-4 homolog (Chico) has been shown to be a crucial regulator of cell size. We have studied Drosophila Akt (Dakt1) and have shown that it is also involved in the regulation of cell size. Furthermore we have performed genetic epistasis tests to demonstrate that in Drosophila, PI3'K, PTEN and Akt comprise a signaling cassette that is utilized during multiple stages of development. In addition, we show that this signaling cassette is also involved in the regulation of cell survival during embryogenesis. This study therefore establishes the evolutionary conservation of this signaling pathway in Drosophila. Oncogene (2000) 19, 3971 - 3977.     

Cutaneous implantation metastasis of cholangiocarcinoma after percutaneous transhepatic biliary drainage

Percutaneous transhepatic biliary decompression is a preoperative surgical adjunct in patients with obstructive jaundice that has been in use since 1973. It is recommended that this procedure be adopted for both palliative treatment in unresectable patients and as a preoperative means of lowering serum bilirubin in patients with potentially resectable malignancies of the pancreas or biliary tract. Metastatic tumor seeding along the transhepatic biliary catheter is an unusual complication resulting from this procedure but there have been a few cases reported in the literature. Below is a report on a 59-year-old woman in whom the percutaneous transhepatic catheter drainage of the biliary tree, performed before surgical resection of a cholangiocarcinoma, caused cutaneous tumor implantation at the catheter site 3 months later. The clinical aspect was morphea-like and histopathologic examination revealed typical features of a dermal metastasis of adenocarcinoma. Immunohistochemistry revealed cytoplasmic positivity for cytokeratin 7-19, specific for the biliary tract epithelium. A review of the literature available led us to conclude that port-site metastasis in patients with obstructive jaundice treated with percutaneous transhepatic biliary decompression was an unusual but possible complication. In fact, many catheter-tract metastatic deposits in the liver parenchyma, detected at autopsy or on operation, are mistakenly identified as hematogenous or lymphatic metastasis and are not attributed to a catheter-related process. We also report on this case because of the atypical morphea-like aspect of the skin metastasis.     

Computed tomography evaluation of metastasis of cutaneous melanoma

PURPOSE: To assess the value of Computed Tomography (CT) in the diagnosis and in morphologic characterization of metastatic melanoma. MATERIALS AND METHODS: The data of total body CT of 124 consecutive patients with melanoma having a Breslow index 1 mm or a positive sentinel lymph node have been retrospectively reviewed. RESULTS: The CT scan showed loco-regional and/or distant metastases in 36 patients (39%). Ten of these (28%) had metastases only to lymph nodes, whereas 26 patients (72%) had multiple metastases. Nodal, pulmonary, brain, subcutaneous, hepatic, adrenal, bone, gastrointestinal, breast and abdominal wall metastases were detected in 80.6%, 47.2%, 25%, 25%, 16.7%, 13.9%, 11.1%, 5.6%, 5.6% and 2.8% of the patients respectively. All the patients with metastases also had a positive sentinel lymph nodes and/or symptoms of metastatic disease. CONCLUSIONS: CT fails to reveal any characteristic feature of metastatic melanoma, but it is of value in the diagnosis of loco-regional and distant metastases in III stage disease.