Clinical and histopathologic features of chordomas in children and young adults.

Chordoma is a tumor of the axial skeleton that is distinctly uncommon in children and adolescents. Previous observations have suggested that chordomas in pediatric patients differ from adult chordomas in presentation, morphology, and behavior. This study examines the clinical and histologic features of chordomas in young patients (< or =25 years old). All cases from the Mayo Clinic files were graphed according to age and a bimodal distribution was observed. The 35 cases representing the youngest population were selected for review. Histopathology ranged from low cellularity tumors with lobulated architecture and abundant myxoid matrix (conventional chordoma), to those with varying amounts of chondroid matrix (chondroid chordoma), to more cellular tumors (atypical chordoma), and finally to neoplasms with high-grade spindle-cell differentiation (dedifferentiated chordoma). Over an average follow-up period of 129 months (range 1 to 501 months), there were 13 deaths (37%) and 3 patients with metastasis. This survival rate was slightly better than the reported mortality rate for adults with chordoma, but there was a subset of young patients (those with atypical chordoma) that had a significantly worse survival rate, suggesting that histologic subtyping may be predictive of prognosis.

Comparison and validation of point of care lactate meters as a replacement for fetal pH measurement.

OBJECTIVE: To validate a point of care lactate device to replace fetal pH measurement. STUDY DESIGN AND METHODS: Cord blood samples drawn immediately following delivery were tested on the Nova Lactate Plus and ARKRAY Lactate Pro, the Corometrics 220 pH System, and the Vitros chemistry analyzer (used as lactate reference). RESULTS: Nova demonstrated a constant positive bias relative to the lactate reference method; while the Lactate Pro correlated well with the reference method up to 6 mmol/L. Receiver operating characteristic (ROC) curve analysis showed optimal sensitivity and specificity for predicting pH<7.20 at lactate values of 6.8 mmol/L for the Nova and 4.8 mmol/L for the Lactate Pro. CONCLUSION: Using Lactate Pro the best cut-off for predicting pH< or =7.20 was 4.8 mM; which coincides with current clinical cut-offs. Thus any lactate device that correlates well with the laboratory reference method can be used with a clinical cut-off of 4.8 mmol/L.

GLUT-1 expression in mesenchymal tumors: an immunohistochemical study of 247 soft tissue and bone neoplasms.

GLUT-1, an erythrocyte-type glucose transporter protein expressed in juvenile hemangiomas, has recently been shown to be a sensitive marker of perineurial cells and their tumors in a small number of cases. However, GLUT-1 expression has not been systematically examined in other mesenchymal neoplasms. Prompted by a recent report of GLUT-1 expression in epithelioid sarcoma, a tumor not generally felt to show perineurial differentiation, we examined GLUT-1 expression in a wide variety of mesenchymal tumors. Sections from 247 mesenchymal tumors of a variety of histologic subtypes were retrieved from our archives and immunostained for GLUT-1 using heat-induced epitope retrieval and the DAKO ADVANCE detection system (DAKO, Carpinteria, CA). Scoring was as follows: negative (<5% of cells), 1+ (5%-25% of cells), 2+ (25%-50% of cells), and 3+ (>50% of cells). All benign nerve sheath tumors showed a peripheral rim of positive normal perineurial cells, with 2 neurofibromas and 3 schwannomas showing more extensive staining. Three of 4 perineuriomas showed strong GLUT-1 expression. All juvenile hemangiomas were GLUT-1 positive. GLUT-1 expression was also seen in a wide variety of benign and malignant mesenchymal tumors. However, GLUT-1 expression was absent in nonjuvenile hemangioma endothelial tumors and in almost all low-grade lesions that enter the histologic differential diagnosis of perineurial tumors, including low-grade fibromyxoid sarcoma, dermatofibrosarcoma protuberans, and myxofibrosarcoma. We conclude that GLUT-1 expression in mesenchymal tumors is by no means specific for perineurial differentiation, but may instead represent upregulation of this protein within hypoxic zones, secondary to upstream activation of proteins such as hypoxia-inducible factor 1-alpha.

Fatal multiorgan failure due to yellow fever vaccine-associated viscerotropic disease.

Yellow fever vaccine-associated viscerotropic disease (YEL-AVD) is a rare complication of yellow fever (YF) vaccination. A previously healthy 22-year-old female died following YF vaccination despite aggressive measures. Serial viral load titers, cytokine levels and host genetic factors were evaluated in an attempt to understand this unusual and lethal outcome. The patient's high-titer vaccine viremia and possibly related minor genetic anomalies provide clues to exploring the etiology of YEL-AVD.