Clinico-genetic aspects of a pediatric non-neurofibromatosis type 1 malignant triton tumor with loss of chromosome X

Malignant triton tumor (MTT) is an aggressive peripheral nerve sheath tumor with rhabdomyoblastic differentiation. Less than 100 cases have been described, being mostly male children with type 1 neurofibromatosis. We report a 6-year-old female with MTT and no diagnostic criteria for neurofibromatosis type 1. Cytogenetic analysis showed a 46,X,-X[4]/46,XX[16] karyotype. She underwent a transfemoral amputation and chemotherapy and is free of disease 15 months after diagnosis. The few cytogenetic studies of MTT described in the literature have been inconclusive. Further cytogenetic analyses are needed to understand the role of chromosome X monosomy in the pathogenesis of this rare tumor. Pediatr Blood Cancer 2012; 59: 13201323. (C) 2012 Wiley Periodicals, Inc.

A Comparative Wet Collapse Buckling Study for the Carcass Layer of Flexible Pipes

When there is a failure on the external sheath of a flexible pipe, a high value of hydrostatic pressure is transferred to its internal plastic layer and consequently to its interlocked carcass, leading to the possibility of collapse. The design of a flexible pipe must predict the maximum value of external pressure the carcass layer can be subjected to without collapse. This value depends on the initial ovalization due to manufacturing tolerances. To study that problem, two numerical finite element models were developed to simulate the behavior of the carcass subjected to external pressure, including the plastic behavior of the materials. The first one is a full 3D model and the second one is a 3D ring model, both composed by solid elements. An interesting conclusion is that both the models provide the same results. An analytical model using an equivalent thickness approach for the carcass layer was also constructed. A good correlation between analytical and numerical models was achieved for pre-collapse behavior but the collapse pressure value and post-collapse behavior were not well predicted by the analytical model. [DOI: 10.1115/1.4005185]

Clinicopathologic and immunohistochemical features of oral neurofibroma

Objective. The purposes of this study were to assess clinical, histopathological and immunohistochemical features of 22 oral neurofibromas (NFs) and discuss with previously described literature, addressing the main aspects regarding the differential diagnosis. Materials and methods. Immunohistochemical reactions included S-100, CD34, GLUT-1, EMA, Ki-67, p53 and Collagen IV and histochemical reactions for Alcian blue. Results. Clinically, the preferential location was the maxillary bones, tongue and buccal mucosa. Microscopically, widely spread spindle-shaped cells with scant cytoplasm and elongated nuclei were observed. Immunostaining revealed that the tumor cells weakly expressed GLUT-1, Collagen IV, Ki-67 and p53. They were variably positive for CD34, S-100 protein and membrane epithelial antigen (EMA). Conclusions. The different types of nerve sheath cells observed in the present series reinforce the presence of heterogeneous population in NFs. The strong positivity for S-100 suggests that the lesions were more composed by S-100-positive Schwann cells than other cells. Besides, the high number of CD34-positive cells suggests that this marker can be useful for the differential diagnosis of NFs against PEN, traumatic neuromas and Schwannomas. Finally, the low immunostaining for p53 and Ki-67 may indicate that NFs massively composed by S-100-positive Schwann cells present low potential of aggressiveness and malignant transformation.

Functional and morphometric differences between the early and delayed use of phototherapy in crushed median nerves of rats

This study evaluated the functional and quantitative differences between the early and delayed use of phototherapy in crushed median nerves. After a crush injury, low-level laser therapy (GaAs) was applied transcutaneously at the injury site, 3 min daily, with a frequency of five treatments per week for 2 weeks. In the early group, the first laser treatment started immediately after surgery, and in the delayed group, after 7 days. The grasping test was used for functional evaluation of the median nerve, before, 10, and 21 days after surgery, when the rats were killed. Three segments of the median nerve were analyzed histomorphometrically by light microscopy and computer analysis. The following features were observed: myelinated fiber and axon diameters, myelin sheath area, g-ratio, density and number of myelinated fibers, and area and number of capillaries. In the proximal segment (site of crush), the nerves of animals submitted to early and delayed treatment showed myelinated fiber diameter and myelin sheath area significantly larger compared to the untreated group. In the distal segment, the myelin sheath area was significantly smaller in the untreated animals compared to the delayed group. The untreated, early, and delayed groups presented a 50, 57, and 81% degree of functional recovery, respectively, at 21 days after injury, with a significant difference between the untreated and delayed groups. The results suggest that the nerves irradiated with low-power laser exhibit myelinated fibers of greater diameter and a better recovery of function.

Prognostication of Soft Tissue Sarcomas Based on Chromosome 17q Gene and Protein Status: Evaluation of TOP2A, HER-2/neu, and Survivin

Topoisomerase 2 alpha (), HER-2/ and are genes that lie on chromosome 17 and correlate with the prognosis and prediction of target-driven therapy against tumors. In a previous study, we showed that TOP2A transcripts levels were significantly higher in soft tissue sarcomas (STS) than in benign tumors and desmoid-type fibromatoses (FM). Because these genes have been insufficiently examined in STS, we aimed to identify alterations in TOP2A and HER-2 expression by fluorescent in situ hybridization and immunohistochemistry, as well as that of survivin, and correlate them with clinicopathologic findings to assess their prognostic value. Eighteen FM and 244 STS were included. Fluorescent in situ hybridization and immunohistochemistry were performed on a tissue microarray. TOP2A and survivin were more highly expressed in sarcomas than in FM. TOP2A was an independent predictor of an unfavorable prognosis; it was combined with formerly established prognostic factors (primarily histologic grade and tumor size at diagnosis) to create a prognostic index that evaluated overall survival. Gene amplification/polysomy (13%) did not correlate with protein overexpression. Survivin and HER-2 expression were not associated with patient outcomes. These findings might become valuable in the management of patients with STS and possibly in the prospective evaluation of responses to new target-driven therapies.