Nonlipidized juvenile xanthogranuloma: an unusual variant with a potential diagnostic pitfall

Juvenile xanthogranuloma (JXG) is a histiocytic inflammatory disorder that can present different histologic patterns. Classic JXG consists of sheets of foamy histiocytes and numerous multinucleated Touton giant cells. Nonlipidized JXG (NJXG) is one of the unusual variants of JXG, consisting of a diffuse monomorphic infiltrate of mononuclear histiocytes, suggesting an aggressive or malignant tumor due the high mitotic index. However, NJXG behaves clinically as classic JXG. We present an unusual case of a 6-year-old boy who presented an exophytic ulcerated nodule on the lower lip diagnosed as NJXG. The boy is currently well without recurrence three years after surgical excision.     

Expression analysis of stem cell-related genes reveal <Emphasis Type="Italic">OCT4</Emphasis> as a predictor of poor clinical outcome in medulloblastoma

Aberrant expression of stem cell-related genes in tumors may confer more primitive and aggressive traits affecting clinical outcome. Here, we investigated expression and prognostic value of the neural stem cell marker CD133, as well as of the pluripotency genes LIN28 and OCT4 in 37 samples of pediatric medulloblastoma, the most common and challenging type of embryonal tumor. While most medulloblastoma samples expressed CD133 and LIN28, OCT4 expression was found to be more sporadic, with detectable levels occurring in 48% of tumors. Expression levels of OCT4, but not CD133 or LIN28, were significantly correlated with shorter survival (P ≤ 0.0001). Median survival time of patients with tumors hyperexpressing OCT4 and tumors displaying low/undetectable OCT4 expression were 6 and 153 months, respectively. More importantly, when patients were clinically stratified according to their risk of tumor recurrence, positive OCT4 expression in primary tumor specimens could discriminate patients classified as average risk but which further deceased within 5 years of diagnosis (median survival time of 28 months), a poor clinical outcome typical of high risk patients. Our findings reveal a previously unknown prognostic value for OCT4 expression status in medulloblastoma, which might be used as a further indicator of poor survival and aid postoperative treatment selection, with a particular potential benefit for clinically average risk patients.     

Surgically treated mediastinal fat necrosis: an exception to conservative treatment

Mediastinal fat necrosis is an important differential diagnosis for acute chest pain in previously healthy patients. Imaging examination is essential to establish this diagnosis, as physical examination can be unhelpful and laboratory tests are non-specific. The treatment of choice is conservative, with non-steroidal anti-inflammatory drugs; surgery is reserved for a few selected cases. We present the case of a 37-year-old male patient with mediastinal fat necrosis, refractory to the conservative management and complicated by growing pleural effusion, which was treated surgically.     

Usefulness of diffusion tensor imaging and fiber tractography in neurological and neurosurgical pediatric diseases

Introduction  

Diffusion tensor imaging (DTI) with fiber tractography (FT) is a recently introduced imaging technique that is unique in providing detailed imaging of white matter (WM) tracts and connectivity between different regions of the brain not easily appreciated with other imaging methods.     

Sealing ability of MTA-Angelus with propyleneglycol in furcal perforations

This study evaluated the sealing ability of gray MTA-Angelus mixed with propyleneglycol in furcal perforations using a bacterial leakage test. Furcal perforations were created in 30 human mandibular molars using a size 3 round bur The samples were divided randomly into 2 experimental groups (n=10) according to the mixing agent. In G1, the MTA powder was mixed with propyleneglycol, while distilled water was used in G2. A 3:1 powder-liquid ratio was used for both groups. The MTA was placed in the perforation with an MTA carrier and condensed with hand pluggers. Non-repaired (n=5) and totally sealed (n=5) perforations served as positive and negative controls, respectively. Bacterial leakage was assessed daily for 30 days in a double-chamber apparatus with Enterococcus faecalis. Data were analyzed using Fisher exact test (p < 0.05) for three leakage periods: 1st to 10th day (P1); 11th to 20th day (P2); and 21st to 30th day (P3). The positive control presented leakage in all specimens within the first 24 hours, while no leakage was observed in the negative control during the experimental period. Leakage was observed in five (50%) of the 10 samples of the propyleneglycol group (G1) and seven (70%) of the distilled water group (G2) by the 20th day, without significant difference between the groups in periods P1 and P2 (p = 0.137). The leakage was significantly lower for G1 than G2 in period P3 (50% versus 100%, respectively, p = 0.016). In this single aerobic bacterial leakage method, the use of propyleneglycol as a vehicle for gray MTA-Angelus increased its sealing ability in furcal perforations at the end of the 30-day experimental period.