Malignant Transformation Of Benign Tumor Research Articles

The Role of Osteosynthesys Materials in the Etiopathology of Bone Malignant Tumors and Reconstruction Possibilities. Case report

The use of osteosynthesis materials in orthopedics is fundamental in the surgical management of patients presenting with various pathologies of the locomotor system, in most cases trauma, but also malign and benign tumors. The risk that these materials could have in inducing malignant transformation of benign tumors or in the onset of primary malignant tumors, was rarely studied. On the one hand, primary malignant tumors of the locomotor system are much less frequent than other kind of neoplasms (for example Ewing sarcoma has an incidence of 1-3 cases / 1.000.000 people / year, ostosarcoma has an incidence of 2 cases / 1.000.000 people / year). On the other hand, usually there is a time window of several years, different from one case to another, from the moment of action of the etiopathogenic factor to the moment of revealing the presence of a neoplastic disease. Based on our clinical practice on a few clinical cases, we intend to study more thoroughly the etiology of primary bone malignant tumors in general and the role of the osteosynthesys materials in this matter especially.

State-of-the-Art Imaging of Salivary Gland Tumors.

MR imaging is the modality of choice in evaluation of salivary gland tumors. Postcontrast MR imaging is adequate for exact localization and extension of salivary gland tumors and multiparametric of diffusion-weighted and dynamic contrast-enhanced MR imaging helps in characterization of benign and malignant salivary gland tumors. Imaging is important for preoperative localization, characterization of salivary gland tumors and locoregional extension, perineural spread, and nodal and distant staging of malignant salivary gland tumors. Imaging has a role in detection of tumor recurrence, monitoring patients after therapy, prediction of malignant transformation of benign tumors, and differentiation of salivary gland tumors from simulating inflammatory and autoimmune disorders.

Gamma Knife radiosurgery for meningiomas in patients with neurofibromatosis Type 2.

Neurofibromatosis Type 2 (NF2) is a rare autosomal dominant disorder predisposing patients to meningiomatosis. The role of stereotactic radiosurgery (SRS) is poorly defined in NF2, and although the procedure has excellent control rates in the non-NF2 population, its utility has been questioned because radiation has been hypothesized to predispose patients to malignant transformation of benign tumors. To the authors' knowledge, this is the first study to examine the use of SRS specifically for meningiomas in patients with NF2. The authors searched a tumor registry for all patients with NF2 who had undergone Gamma Knife radiosurgery (GKRS) for meningioma in the period from January 1, 1999, to September 19, 2013, at a single tertiary care cancer center. Medical records were retrospectively reviewed for patient and tumor characteristics and outcomes. Among the 12 patients who met the search criteria, 125 meningiomas were identified, 87 (70%) of which were symptomatic or progressive and thus treated with GKRS. The median age at the first GKRS was 31 years (interquartile range [IQR] 27-37 years). Five patients (42%) had multiple treatments with a median of 27 months (IQR 14-50 months) until the subsequent GKRS. The median follow-up in surviving patients was 43 months (IQR 34-110 months). The 5-year local tumor control and distant treatment failure rates were 92% and 77%, respectively. Toxicities occurred in 25% of the GKRS treatments, although the majority were Grade 1 or 2. At the last follow-up, 4 patients (33%) had died a neurological death at a median age of 39 years (IQR 37-46 years), and their cases accounted for 45% of all tumors, 55% of all treated tumors, and 58% of all GKRSs. Univariate analysis revealed several predictive variables for distant failure, including male sex (HR 0.28, 95% CI 0.086-0.92, p = 0.036), age at distant failure (HR 0.92, 95% CI 0.90-0.95, p < 0.0001), and prior number of GKRS treatments (HR 1.2, 95% CI 1.1-1.4, p = 0.0049). Local failure, maximum size of the treated tumor, delivered tumor margin dose, and WHO grade were not significant. On multivariate analysis, age at distant failure (HR 0.91, 95% CI 0.88-0.95, p < 0.0001) and prior number of GKRSs (HR 1.3, 95% CI 1.1-1.5, p = 0.004) remained significant. No malignant transformation events among treated tumors were observed. Radiosurgery represents a feasible modality with minimal toxicity for NF2-associated meningiomas. Increasing patient age was associated with a decreased rate of distant failure, whereas an increasing number of prior GKRS treatments predicted distant failure. Further studies are necessary to determine the long-term patterns of treatment failure in these patients.

The presence of TP53 and dedifferentiation of low-grade glioma: A rare possible adverse effect of radiotherapy?

Radiotherapy and radiosurgery are important modes of treatment for benign and malignant brain tumors. Radiation-induced tumors and radiation-induced malignant transformation of tumors have been described in many reports. Radiotherapy is one of the standard treatments for intracranial glial tumors. However, there is limited discussion of radiation carcinogenesis in glioma treatment. We present a 58-year-old male who was initially diagnosed to have low-grade glioma in an eloquent area of the brain by stereotactic biopsy. The tumor progressed rapidly after radiotherapy and a second stereotactic biopsy was done. Based on the WHO classification, the diagnosis for the second specimen was high-grade glioma. Histopathology showed that the expression of TP53 had increased from 40% to 60% in the second specimen. The finding was consistent with other reports of the malignant transformation of benign tumor after radiotherapy. Radiation carcinogenesis may be one of the causes for tumor progression to high-grade within 6 months. The effect of radiotherapy on the control of glioma is well-documented. Radiation carcinogenesis, which could cause malignant transformation of benign brain tumors, could also be observed in low-grade glioma. This report clearly indicates that caution is warranted regarding the use of radiotherapy for glial tumors, especially for low-grade gliomas.

Malignant Transformation of a Vestibular Schwannoma Following Gamma Knife Radiosurgery: Case Report and Review of the Literature

Introduction: Whether used in a primary or adjuvant fashion for treatment of brain neoplasms, external beam radiation therapy is associated with the development of secondary malignancy and malignant transformation of benign tumors. Radiosurgery is designed to minimize these risks by delivering a highly targeted, cytotoxic dose of radiation to the tumor. Nonetheless, there is a growing body of literature describing patients with malignant transformation of primary benign tumors after radiosurgery, including vestibular schwannoma (VS).

Mammary tumors in splenectomized rats.

The objective of this study was to examine how splenectomy affects the immune response, particularly T cells, in chemically-induced mammary tumors. Female rats were splenectomized and then exposed to 9,10-dimethyl-1,2-benz(a)anthracene (DMBA) to induce mammary tumors. Splenectomy significantly decreased the rate of tumor appearance and their malignant transformation. The tumor latency period in splenectomized rats was 12.0+/-0.9 weeks compared to 9.7+/-0.5 wk in intact controls, and malignancy appeared in 45% of splenectomized rats, compared to 70% in controls. By the end of the experiment, the total number of tumors and their size were similar in both groups. Blood CD4+ and CD8+ T cell concentrations were similar in tumor-bearing and tumor-free splenectomized animals, but in both groups CD4- and CD8- lymphocytes decreased sharply compared to control animals. In tumor-bearing rats, splenectomy also resulted in significantly more circulating natural killer cells. The spleens of tumor-bearing control rats had significantly fewer CD4+ and CD8+ lymphocytes and more CD4- and CD8- lymphocytes and natural killer cells than did their blood. In conclusion, splenectomy inhibits the early stages of tumorigenesis and reduces the rate of malignant transformation of benign tumors, but does not prevent the progress of carcinogenesis. Differences between splenectomized (operated) and intact rats to the effect of DMBA can be explained by an increase in non-specific resistance of splenectomized rats as a result of operation.

1H NMR Spectroscopy: An Approach to Evaluation of Diseased Skin In Vivo

1H nuclear magnetic resonance (NMR) spectroscopy was tested for its applicability in evaluating diseased skin. In order to explore potential spectral markers characteristic of diseased tissue, perchloric acid (PCA) extracts of psoriasis and malignant melanoma tissues were compared with normal skin, and changes in melanoma after heat treatment were monitored. In psoriatic plaque extract, the spectral peak intensity ratios of Glu: Ser, creatine: Gly, and taurine: Ala were approximately three-fold compared with symptom-free or normal skin, whereas Val: Leu/Ile was one-half the normal skin ratio. In melanoma extracts, the phosphorylcholine (PC)/glycerophosphorylcholine (GPC): Ala, Glu: Ser, and lactate: Ala ratios were five-, three-, and two-fold higher, respectively, than normal skin and the Val: Leu/Ile ratio was two-thirds of normal skin. With heat treatment, PC/GPC: Ala and Glu: Ser ratios decreased, whereas lactate: Ala and Val: Leu/Ile ratios increased three-fold and one-third, respectively. Results indicate that 1H NMR spectroscopy is a sufficiently sensitive technique to distinguish normal from diseased skin. The main attraction of this technique lies in the possibility of non-invasive study of various skin diseases, malignant transformation of benign tumors, and responses to treatment. Several methodologic problems remain to be resolved before a meaningful interpretation of in vivo observations becomes feasible. Correlation of in vivo and in vitro findings is an essential step toward this goal.