A model for preservation of thymocyte-depleted thymus.

DiGeorge syndrome is a disorder caused by a microdeletion on the long arm of chromosome 22. Approximately 1% of patients diagnosed with DiGeorge syndrome may have an absence of a functional thymus, which characterizes the complete form of the syndrome. These patients require urgent treatment to reconstitute T cell immunity. Thymus transplantation is a promising investigational procedure for reconstitution of thymic function in infants with congenital athymia. Here, we demonstrate a possible optimization of the preparation of thymus slices for transplantation through prior depletion of thymocytes and leukocyte cell lineages followed by cryopreservation with cryoprotective media (5% dextran FP 40, 5% Me2SO, and 5% FBS) while preserving tissue architecture. Thymus fragments were stored in liquid nitrogen at -196°C for 30 days or one year. The tissue architecture of the fragments was preserved, including the distinction between medullary thymic epithelial cells (TECs), cortical TECs, and Hassall bodies. Moreover, depleted thymus fragments cryopreserved for one year were recolonized by intrathymic injections of 3×106 thymocytes per mL, demonstrating the capability of these fragments to support T cell development. Thus, this technique opens up the possibility of freezing and storing large volumes of thymus tissue for immediate transplantation into patients with DiGeorge syndrome or atypical (Omenn-like) phenotype.

A model for preservation of thymocyte-depleted thymus

DiGeorge syndrome is a disorder caused by a microdeletion on the long arm of chromosome 22. Approximately 1% of patients diagnosed with DiGeorge syndrome may have an absence of a functional thymus, which characterizes the complete form of the syndrome. These patients require urgent treatment to reconstitute T cell immunity. Thymus transplantation is a promising investigational procedure for reconstitution of thymic function in infants with congenital athymia. Here, we demonstrate a possible optimization of the preparation of thymus slices for transplantation through prior depletion of thymocytes and leukocyte cell lineages followed by cryopreservation with cryoprotective media (5% dextran FP 40, 5% Me2SO, and 5% FBS) while preserving tissue architecture. Thymus fragments were stored in liquid nitrogen at -196°C for 30 days or one year. The tissue architecture of the fragments was preserved, including the distinction between medullary thymic epithelial cells (TECs), cortical TECs, and Hassall bodies. Moreover, depleted thymus fragments cryopreserved for one year were recolonized by intrathymic injections of 3×106 thymocytes per mL, demonstrating the capability of these fragments to support T cell development. Thus, this technique opens up the possibility of freezing and storing large volumes of thymus tissue for immediate transplantation into patients with DiGeorge syndrome or atypical (Omenn-like) phenotype.

DAX1 Overexpression in Pediatric Adrenocortical Tumors: A Synergic Role with SF1 in Tumorigenesis.

DAX1 transcription factor is a key determinant of adrenogonadal development, acting as a repressor of SF1 targets in steroidogenesis. It was recently demonstrated that DAX1 regulates pluripotency and differentiation in murine embryonic stem cells. In this study, we investigated DAX1 expression in adrenocortical tumors (ACTs) and correlated it with SF1 expression and clinical parameters. DAX1 and SF1 protein expression were assessed in 104 ACTs from 34 children (25 clinically benign and 9 malignant) and 70 adults (40 adenomas and 30 carcinomas). DAX1 gene expression was studied in 49 ACTs by quantitative real-time PCR. A strong DAX1 protein expression was demonstrated in 74% (25 out of 34) and 24% (17 out of 70) of pediatric and adult ACTs, respectively (χ(2)=10.1, p=0.002). In the pediatric group, ACTs with a strong DAX1 expression were diagnosed at earlier ages than ACTs with weak expression [median 1.2 (range, 0.5-4.5) vs. 2.2 (0.9-9.4), p=0.038]. DAX1 expression was not associated with functional status in ACTs. Interestingly, a positive correlation was observed between DAX1 and SF1 protein expression in both pediatric and adult ACTs (r=0.55 for each group separately; p<0.0001). In addition, DAX1 gene expression was significantly correlated with SF1 gene expression (p<0.0001, r=0.54). In conclusion, DAX1 strong protein expression was more frequent in pediatric than in adult ACTs. Additionally, DAX1 and SF1 expression positively correlated in ACTs, suggesting that these transcription factors might cooperate in adrenocortical tumorigenesis.

Texture image analysis in differentiating malignant from benign adrenal cortical tumors in children and adults.

OBJECTIVE: To investigate the possible role of chromatin texture parameters, nuclear morphology, DNA ploidy and clinical functional status in discriminating benign from malignant adrenocortical tumors (ACT). PATIENTS AND METHODS: Forty-eight cases of clinically benign (n=40) and clinically malignant (n=8) ACT with a minimum of 5-years' follow-up were evaluated for chromatin texture parameters (run length, standard deviation, configurable run length, valley, slope, peak and other 21 Markovian features that describe the distribution of the chromatin in the nucleus), nuclear morphology (nuclear area, nuclear perimeter, nuclear maximum and minimum diameter, nuclear shape), and DNA ploidy. Nuclear parameters were evaluated in Feulgen-stained 5 mum paraffin-sections analyzed using a CAS 200 image analyzer. RESULTS: Since ACTs present different biological features in children and adults, patients were divided into two groups: children (< or = 15 years) and adults (>15 years). In the group of children DNA ploidy presented a marginal significance (p=0.05) in discriminating ACTs. None of the parameters discriminated between malignant and benign ACT in the adult group. CONCLUSION: ACTs are uncommon and definitive predictive criteria for malignancy remain uncertain, particularly in children. Our data point to DNA content evaluated by image analysis as a new candidate tool for this challenging task. Texture image analysis did not help to differentiate malignant from benign adrenal cortical tumors in children and adults.

DNA ploidy in cervical lesions assessed by computed image analysis: relation to histopathology.

OBJECTIVE: To assess the different patterns of DNA nuclear content in cervical intraepithelial neoplasia. STUDY DESIGN: DNA nuclear content patterns (DNA ploidy) were assessed in 82 paraffin embedded samples diagnosed as chronic cervicitis CIN 1, CIN 2 and CIN 3 by image analysis using the CAS200 BD System. These results were compared to the consensus diagnosis of two pathologists. The chi-square test was used to evaluate the results of classificatory variables (CIN 1, CIN 2 and CIN 3). RESULTS: Aneuploidy was found in 86% of CIN 3; 59% CIN 2; 26%% CIN 1. All samples classified as chronic cervicitis were diploid. CONCLUSIONS: The DNA nuclear content was found to parallel the three grades of the histological WHO classification. Aneuploidy was strongly associated with the high-grade lesions; the detection of a subset aneuploidy of low grade lesions would suggest a indicate closer follow-up of these cases.

p53 as a prognostic factor in adrenocortical tumors of adults and children.

Mutations of the tumor suppressor gene p53 have been considered to be important determinants in several kinds of human cancer. Accumulation of p53 protein has been reported to correlate with more aggressive clinical behavior in some neoplasms. The role of p53 expression in adrenal cortical tumors (ACT) has not been elucidated but some studies have suggested its correlation with malignant behavior. Our objective was to determine if there is a correlation between the expression of immunoreactive p53 and the biological behavior of ACT. Fifty-seven ACT (21 from children and 36 from adults) were evaluated for p53 expression by immunohistochemistry in formalin-fixed paraffin-embedded tissue and analyzed in terms of outcome. The p53 parameter was utilized semiquantitatively. Tumors were classified as p53 negative when no positivity was observed, or when only few cells showed weak positivity (0/1+) and scored as p53 positive when there was a diffuse and strong nuclear positivity (2+/3+). In children, p53 positivity was associated with clinically malignant ACT and p53 negativity was associated with clinically benign ACT (P = 0.026). In adults' ACT, p53 positivity had an effect on disease-free survival (P<0.001) and also correlated with Weiss score, with a cutoff = 4 (P = 0.04). p53 expression was related to the clinical behavior of ACT in both children and adults and these findings seem to support a role for p53 in ACT progression.

p53 as a prognostic factor in adrenocortical tumors of adults and children

Mutations of the tumor suppressor gene p53 have been considered to be important determinants in several kinds of human cancer. Accumulation of p53 protein has been reported to correlate with more aggressive clinical behavior in some neoplasms. The role of p53 expression in adrenal cortical tumors (ACT) has not been elucidated but some studies have suggested its correlation with malignant behavior. Our objective was to determine if there is a correlation between the expression of immunoreactive p53 and the biological behavior of ACT. Fifty-seven ACT (21 from children and 36 from adults) were evaluated for p53 expression by immunohistochemistry in formalin-fixed paraffin-embedded tissue and analyzed in terms of outcome. The p53 parameter was utilized semiquantitatively. Tumors were classified as p53 negative when no positivity was observed, or when only few cells showed weak positivity (0/1+) and scored as p53 positive when there was a diffuse and strong nuclear positivity (2+/3+). In children, p53 positivity was associated with clinically malignant ACT and p53 negativity was associated with clinically benign ACT (P = 0.026). In adults' ACT, p53 positivity had an effect on disease-free survival (P<0.001) and also correlated with Weiss score, with a cutoff = 4 (P = 0.04). p53 expression was related to the clinical behavior of ACT in both children and adults and these findings seem to support a role for p53 in ACT progression

An inherited mutation outside the highly conserved DNA-binding domain of the p53 tumor suppressor protein in children and adults with sporadic adrenocortical tumors.

Mutations of the p53 tumor suppressor gene are the single most common genetic alterations in human cancers. Recently, a distinct nucleotide substitution was identified in exon 10 of the p53 gene, leading to an Arg337His mutation in 97% of children with adrenocortical tumors from Southern Brazil. In the present study, we investigated the presence of this mutation in a larger series of 55 patients (37 adults and 18 children) with benign and malignant sporadic adrenocortical tumors. None of the patients had family cancer histories that conformed to the criteria for Li-Fraumeni syndrome. Twenty-one asymptomatic close relatives of patients with p53 mutations and 60 normal unrelated individuals were also studied. The missense Arg337His mutation was identified in 19 patients (14 children and 5 adults), and 8 of 11 cases studied had LOH. Among the 19 patients with the Arg337His mutation, only one boy and three adults showed fatal evolution or recurrent metastases. This mutation was also identified in heterozygous state in asymptomatic first-degree relatives of the patients, indicating that Arg337His mutation was inherited in most cases. In contrast, this mutation was not found in 120 alleles of normal unrelated controls. In conclusion, the germ line Arg337His mutation of p53 protein is present at a high frequency (77.7%) in children with benign or malignant sporadic adrenocortical tumors, but it is not restricted to the pediatric group, since 13.5% of adults with adrenocortical tumors also had this mutation. The presence of this mutation was related to unfavorable prognosis in most of the adults, but not in the children with adrenocortical tumors.

Simultaneous occurrence of advanced neuroblastoma and acute myeloid leukemia.

The authors report the case of a 4-year-old boy with a diagnosis of stage IV neuroblastoma (NB), who had been treated with 6 cycles of cyclophosphamide, doxorubicin, cisplatin, and etoposide for 12 months. The patient reached partial remission and presented a diagnosis of acute myelomonocytic leukemia (M4 AML), confirmed by immunophenotyping. After 2 months of therapy for leukemia, the child died with both malignancies in activity. A necropsy histologically confirmed the simultaneity of the two diseases. The authors review the possibilities of this association. The review leads to the conclusion that AML can occur as a secondary malignancy after the onset of the neuroblastoma, or be suggested by a misdiagnosis. The simultaneous occurrence of both as described here is not, however, found in the literature, to the best of the authors' knowledge.

Adrenocortical carcinoma: clinical and laboratory observations.

BACKGROUND: The clinical features and natural history of adrenocortical carcinoma are highly dependent on the type of center reporting their experience. Observations from oncology services suggest a high incidence of nonfunctioning tumors, whereas reports from endocrine clinics emphasize excessive corticoid and androgen production in the majority of tumors. The incidence rate and natural history of childhood adrenal carcinoma generally has been under emphasized. METHODS: Over the past 17 years, the authors have evaluated and treated 47 patients with adrenocortical carcinoma referred to the University of Sao Paulo, 22 of whom were children. RESULTS: There is a bimodal age incidence of adrenal carcinoma, with the disease peaking in the first and fourth decades of life. Childhood adrenal carcinoma is characterized by a high rate of incidence of virilization, marked overproduction of androgens, and a less aggressive clinical course, and appears to be more amenable to surgical and other therapeutic modalities. By contrast, adrenocortical carcinoma occurring in adults presents more commonly as a mixed Cushing and virilizing syndrome, with overproduction of corticoids and androgens and a far more aggressive clinical course, leading to rapid death within months or years. Nonfunctioning adrenocortical carcinoma is less common; it generally occurs in older adults and exhibits a rapid downhill course. Modern day imaging methods have improved the diagnosis and staging of adrenal carcinoma greatly. In the authors' experience, the histologic criteria of Weiss appeared to predict tumor prognosis most accurately, whereas immunologic markers, cytoskeletal markers, DNA ploidy, cell phase markers, and oncogenic probes have yielded inconsistent results to date. Surgical removal of a localized tumor remains the best hope for long term survival. Medical therapy with mitotane and its successors in patients with Stage III or IV (MacFarlane system as modified by Sullivan et al.) disease appear to have added little to longevity or quality of life. CONCLUSIONS: When diagnosed in children, adrenal carcinoma is associated with virilism and a less aggressive natural history; however, when it occurs in adults, the disease presents more commonly as a mixed Cushing-virilizing syndrome and has a virulent course. The Weiss histologic criteria appear to correlate best with disease prognosis, but other histochemical, cell cycle, and genetic markers have not, to date, aided in disease management.

[Immunohistochemical study of HLA-DR expression in superficial epithelium and in lamina propria of colonic mucosa in children with Crohn's disease and nonspecific ulcerative colitis]. / Estudo imunohistoquímico da expressão HLA-DR no epitélio superficial e na lâmina própria da mucosa colônica de crianças portadoras de doença de Crohn e retocolite ulcerativa inespecífica.

Some researches have stressed the importance of expression HLA-DR on the superficial epithelium and on the lamina propria of the colonic mucosa of patients with ulcerative colitis and Crohn disease. In this research the histological characteristics of the expression HLA-DR on the resident mucosa of both these illness were quantified and analysed. Twelve Crohn disease, 19 ulcerative colitis and 10 specimen of the rectal mucosa, representing the control group according to the following model were studied: I period = pre-treatment, II period = up two years of evolution and III period = more than two years of treatment. The expression HLA-DR was identified by the monoclonal HLA-DR (DAKO) in the resident mucosa specimen by the immunoperoxidase method. The quantification of the expression HLA-DR on the lamina propria was done through the chromatic computer images analysis that express the area (micron2) used by the positive HLA-DR cells and the superficial epithelium in percentage by a semi quantifier evaluation. On the lamina propria of the illness mucosa, the expression HLA-DR was increased in all the studied periods when compared with the control group, but without statistics differences. The distribution of the expression HLA-DR on the lamina propria was done to the corresponding localization to the macrophages and to the B lymphocytes. The superficial colonial epithelium of the ulcerative colitis and Crohn disease patients was in 86.95% and in 80.96% respectively HLA-DR positive in the three periods. The superficial epithelium of all the rectal mucosa of the control group did not show the HLA-DR expression. The presence of the HLA-DR expression on the superficial colonial epithelium of the ulcerative colitis and Crohn disease patients and its absence in the control group was a very important found in this research. It is a consense among several authors that the HLA-DR expression represents a intense local action of the inductorious cytokines of this expression in the colonic mucosa of the ulcerative colitis and Crohn disease patients, representing its activation in a answer to the invasor antigen in the intestinal mucosa. The study of the HLA-DR expression in the lamina propria was not conclusive, because the result did not represent a significative difference in relation with the control.

Activating mutation of the stimulatory G protein (gsp) as a putative cause of ovarian and testicular human stromal Leydig cell tumors.

Activating mutations of the G protein genes have been associated with the development of several endocrine neoplasms. Such activating mutations, gip2, affecting the alpha-subunit of the G alpha i2 protein were previously described by a single group in 30% of ovarian sex cord stromal tumors. Other activating mutations of the alpha-subunit of the Gs (gsp) have been identified in GH-secreting and nonfunctioning pituitary tumors, autonomous thyroid adenomas, and all affected McCune-Albright tissues, but not in sex cord stromal tumors. In the present study, we investigated the presence of gip2 and gsp mutations in 14 human sex cord stromal tumors. Six Leydig cell tumors (4 ovaries and 2 testes), 2 thecomas, 2 granulosa cell tumors, 3 androblastomas, and 1 gonadoblastoma (sex cord and germ cell) were included in this study. Genomic DNA was obtained from either fresh-frozen tumor tissues or paraffin-embedded sections and in some cases from blood samples. Using PCR, denaturing gradient gel electrophoresis, and direct sequencing, we detected 4 tumors (66.6%) with the gsp mutation (R201C) in our series of ovarian and testicular Leydig cell tumors. In contrast, no gip2 mutations were found in any of the sex cord stromal tumors studied. In conclusion, our findings suggest that the putative oncogene gsp may play a significant role in the molecular mechanism of these tumors.

[Immunohistological study of T-lymphocytes (total and helper) and B-lymphocytes of the colonic mucosa in children with Crohn's disease and non-specific ulcerative colitis]. / Estudo imunohistológico do linfócito T (total e auxiliador) e do linfócito B da mucosa colônica de crianças portadoras de doença de Crohn e retocolite ulcerativa inespecífica.

For one to understand better the immunological mechanism in the colonic mucosae of inflammatory bowel disease, 19 children with ulcerative colitis and 12 children with Crohn's disease were studied. The inflammatory cells identified by the immunoperoxidase technique and specific markers for total T lymphocytes (CD3), helper T lymphocytes (CD4) and B lymphocytes (CD20) in differents evolutionary periods of the disease were analysed. PI (before treatment), PII (until two years of treatment) and PIII (with more than two years of treatment). In general, all marker studied in this research, presented higher averages if comparing to the control group with different degrees of significance in the different studied periods. The marker CD3, of the total T lymphocyte, increased in the epithelial (superficial and glandular) and in the lamina propria of the involved mucosae in relation to the controlled ones, was diffusely distributed over the mucosae, concentrating itself around the microgranulomas and the nodules lymphoids. In Crohn's disease, PI, its average differed significantly from the controlled ones. Similar behave was seen in the marker CD20 of the lymphocytes in the involved mucosae, whole averages were superior in relation to the controlled ones; thought, only in the PI of the Crohn's disease this difference had been significant. The immunochromatic cells CD3 distributed themselves diffusely over the involved mucosae, concentrating themselves in the interior of the lymphoides nodules and in the injured areas, near the macrophages. The marker CD4, of helper T lymphocyte also presented in the involved mucosae high averages in relation to the controlled mucosae, but without estatistic significance. The CD4 cells distributed themselves diffusely over the whole thickness of the involved mucosae, concentrating themselves around the lymphoids nodules and microgranulomas. These results confirm the participation of these elements in the pathogenesis of inflammatory bowel disease, but did not permit the establishment of any discriminatory criteria between ulcerative colitis and Crohn's disease. The results of positive correlation between the increased of CD4 and CD20 in ulcerative colitis and CD3 and CD20 in Crohn's disease show clearly the immunoregulation action of the CD4+ cells over clonal expansion and the differenciation of the B lymphocytes from plasmocytes and the IgG syntese.

Primary malignant epithelial tumors of the liver in children: a study of DNA content and oncogene expression.

Primary malignant epithelial tumors of the liver (PMETL) are rare in the pediatric age group, and very little is known about their biology as compared with adult tumors. The prognostic value of the DNA contents measured by image analysis and expression of oncogene c-erb2 and tumor suppressor gene p53 were studied in 30 cases of PMETL in children, including 24 with hepatoblastomas (HB) and 6 with hepatocellular carcinomas (HCC). p53 overexpression was detected in 12 out of 26 cases (46.0%), or in 3 of 5 HCC and 9 of 21 HB cases. A relatively high concordance of staining was observed with the two antibodies used (clone DO7, Dako and clone DO1, Santa Cruz Biotechnology). c-erb-B2 did not yield the characteristic membrane staining in any of the 27 cases in which reliable staining was obtained. However, 1 out of 4 patients with HCC and 1 of 23 with HB revealed strong granular cytoplasmic staining in several neoplastic cells. Interestingly, these were two of the three aneuploid multiploid cases. DNA histograms of 13 out of 29 cases (54.8%) were classified as DNA aneuploid (5/6 HCC and 8/23 HB): nine were hyperdiploid, one was hypodiploid (1HB), and three were multiploid (2HB and 1HCC). In the HB group, DNA aneuploidy was strongly associated with embryonal histological areas, suggesting that a disturbance in the process of cell differentiation is associated with marked genetic aberrations. Only the group of HB was submitted to univariate analysis of survival by the Kaplan-Meier method for age (< 24 months vs. > or = 24 months), sex, preoperative chemotherapy (yes vs. no), residual disease (metastasis, and/or unresectable tumor), p53 expression by immunohistochemistry (positive vs. negative), and DNA ploidy (diploid vs. aneuploid). Only residual disease at the time of diagnosis (P < 0.017) and preoperative chemotherapy (0.030) were found to be negatively correlated with biological behavior, estimated as overall survival. DNA aneuploidy tumors (P < 0.125) and male patients (P = 0.123) showed a trend toward a more aggressive clinical behavior, although the difference was not statistically significant. Combining DNA ploidy and residual disease, patients were categorized into three groups: group I, patients with no adverse prognostic factors, i.e., diploid tumors without residual disease; group II, patients with only one adverse prognostic factor, i.e., aneuploid tumor or residual disease; and group III, patients with both adverse factors, aneuploid tumors and residual disease at time of diagnosis. A log-rank test comparing the three survival curves showed a statistically significant difference between them (P < 0.003). Although the series of cases is small, the results of this study highlight the importance of including DNA ploidy in the protocols designed for HB in children by international cooperative groups.

[Immunohistochemical study of colonic mucosa macrophages in children with Crohn's disease and ulcerative colitis]. / Estudo imunohistoquímico dos macrófagos na mucosa colônica em crianças na doença de Crohn e na retocolite ulcerativa inespecífica.

In this research the histological characteristics of the macrophages on the colonic mucosa in Crohn's disease and ulcerative colitis were quantified and analysed. Twelve Crohn's disease, 19 ulcerative colitis and 10 specimen of the rectal mucosa, representing the control group according to the followed model, were studied: I period (PI) = pre-treatment, II period (PII) = up two years of evolution and III period (PIII) = more than two years of evolution. The macrophages were identified in a colonic mucosa by the monoclonal CD68 through the immunoperoxidase method. The macrophages quantification was done by chromatic computer images analysis, that express the area (mm2) used by the CD68 positive cells, in percentage. The percentage of the area used by the macrophages was increased in both diseases, in all the studied periods, when compared with the control group, but without statistic significance. The macrophages' distribution inside the control group mucosa was subepithelial, while in the illness group, it reached all the mucosa that was concentrated on the basis of ulcers and all long the fissures. On the Crohn's disease the CD68 positive cells facilited the identification of the microgranulomas, sometimes unnoticed in the hematoxiline-eosine. Although there was no difference between patients and control group in the macrophages area, the difference in the distribution could suggest the macrophages' participation on the injure in both diseases although they do not permit a differential diagnosis because of the variety of the values. The CD68 did not identify the different functional status of the macrophages, but their position in the mucosa suggest that, in terms of fissures and ulcers, their mainly function should be the phagocitosis and in the other cases, they have been the cells that should show the antigens and that recruit the other inflammatory cells.

Liver biopsy in neonatal cholestasis: a review on statistical grounds.

The aim of this study was to improve the accuracy of the histopathologic diagnosis in the differential diagnosis between obstructive and nonobstructive forms of neonatal cholestasis, using this clinical situation as a model for a mathematical approach. The study was blind, and we performed it in two steps. In the first step, 49 histologic parameters were visually estimated and were scored on a scale of 0 to 4+ in 100 liver biopsy specimens obtained between 1980 and 1985 from 78 patients with neonatal cholestasis. Forty-eight of these 100 specimens were from patients with final diagnosis of obstructive cholestasis (Group I), and 52 were from patients with nonobstructive cholestasis (Group II). The age range was 3 to 24 weeks (median, 12.5 wk). Twelve histologic variables were selected by chi 2 and Fisher's exact test (P < .05). Next, a series of combinations among these variables were submitted to statistical analysis by logistic regression method, defining a six-variable model that had the most powerful predictive value to classify the type of cholestasis. The variables were portal ductal proliferation, bile plugs in portal bile ductules, portoportal bridges, neutrophils, hepatocyte swelling, and multinucleated giant hepatocytes. The score obtained by this model correspond to the probability of a case belonging to Group I. The accuracy, sensitivity, and specificity rates were 94.0%. In the second step, the model was applied to a new sample of 74 needle-liver biopsy specimens obtained between 1990 and 1995, 45 from patients in Group I and 29 from patients in Group II. The age range was 3 to 15 weeks (median, 8 wk). The accuracy, sensitivity, and specificity rates were 90.5%, 100%, and 75.9%, respectively. In our diagnostic routine, this score has been systematically reported and has been helpful in orienting the therapeutic decision in this group of patients.

Nasal chondroma: a case report and review of the literature.

Although rare tumors, chondromas will on occasion be encountered by the otolaryngologist in his routine daily practice. The authors describe a nasal myxochondroma in an 8-year-old child, which was removed satisfactorily surgically, with no signs of recurrence even after 4 years of follow-up. Because chondromas may also present as nasal polyps, the knowledge of cartilaginous tumors in the nose plays a pivotal role for a better approach to these patients.

Dedifferentiated cystic nephroma with malignant mesenchymoma as the dedifferentiated component.

Cystic tumors of the kidney are uncommon and usually do not have solid areas. We report a predominantly cystic renal tumor with solid anaplastic component showing rhabdomyoblastic and cartilaginous differentiation in a 26-month-old girl. Terminology and pathogenesis of tumor progression are discussed along with a review of reports of tumors associated with cystic nephroma.