Osteoblastoma of the nasal cavity arising from the perpendicular plate of the ethmoid bone.

The presence of a benign osteoblastoma in the ethmoid sinus is rare and only a few cases have been reported. This is a case of a benign osteoblastoma arising from the perpendicular plate of the ethmoid bone with extension to the nasal cavity. The diagnosis and management of this unusual lesion, as well as the histopathology and the imaging characteristics are reviewed. We also review the previously reported cases of benign osteoblastomas of different origin, with nasal cavity involvement.

P21/waf1 protein expression in nasopharyngeal carcinoma. Comparative study with PCNA, p53 and MDM-2 protein expression.

We investigated the immunohistochemical expression of p21/waf1 protein in 59 cases of nasopharyngeal carcinomas (NPC) and compared p21 expression with PCNA, p53 and mdm2 protein expression. We found p21, PCNA, p53 and mdm2 in 59/59, 59/59, 18/59 and 12/59 nasopharyngeal carcinomas, respectively. We observed a tendency to a relationship between high expression of PCNA (> 25% positivity in tumour cells) and low expression of p21 protein. Parallel p53/p21 protein expression was found in 18 cases. Twelve were also mdm2 positive. This pattern may represent NPC with wild type (wt) p53 since mdm2 and p21 proteins are inducible by wt p53 gene. In these cases p53 protein expression may be due to stabilisation to mdm2 protein. This could be important in the pathogenesis of these cases since mdm2 may deregulate the p53-dependent growth suppressive pathway. Discordant p53-/p21+ protein expression was found in 41 cases. All were also mdm2 negative. This pattern suggests immunohistochemically undetectable wt p53 gene which is able to induce p21 protein expression.

p53 protein expression in breast carcinomas. Comparative study with the wild type p53 induced proteins mdm2 and p21/waf1.

The aim was to investigate the pattern of expression of p53 protein and two wild-type (wt) p53-induced proteins (mdm2 and p21/waf1), as an indirect way of assessing p53 gene status in breast carcinomas. Formalin-fixed paraffin embedded tissue from 102 cases of breast carcinomas comprising mostly ductal carcinomas (88 cases) was stained by immunohistochemistry for p53, mdm2 and p21/waf1 proteins. We found p53, mdm2 and waf1/p21 protein expression in 33/102, 20/102 and 38/102 breast carcinomas, respectively. Parallel p53/mdm2 protein expression was found in 9 cases. Five were also p21/waf1 positive. Discordant p53+/ mdm2-protein expression was found in 24 cases. Nine were p21/waf1 positive and the remaining fifteen were p21/waf1 negative. The patterns mdm2+/p53-/p21- and p21+/p53-(+)/mdm2- were found in 6 and 20 cases, respectively. Parallel p53/mdm2/p21 protein expression may represent breast carcinomas with wt p53 gene since mdm2 and p21 proteins are inducible by wt p53 gene. In these cases p53 protein expression may be due to stabilisation to mdm2 protein. This could be important in the pathogenesis of these cases since mdm2 may deregulate the p53-dependent growth suppressive pathway. Discordant p53+/mdm2-/p21- protein expression may represent breast carcinomas with p53 gene mutations unable to activate expression of mdm2 and p21 proteins. Breast carcinomas with p53+/mdm2/p21+ protein expression may have either wt p53 with deregulated mdm2 gene expression or mutated p53 gene with p53-independent p21 expression. Cases with only mdm2 expression may represent tumours with mdm2 gene amplification or overexpression and cases with only p21 expression may reflect p53-independent regulation of p21 protein.

MIB1 (Ki-67) expression in non-Hodgkin's lymphomas.

The MIB1 monoclonal antibody which is used as a marker of cell proliferation was studied by immunohistochemistry on formalin-fixed and paraffin embedded biopsy specimens of lymph nodes in 40 high- and 46 lowgrade cases of non-Hodgkin's lymphomas (NHL) classified according to the Kiel classification. All cases were found to display nuclear MIB1 staining. A statistically significant difference (P < 0.005) was found between high- and low grade NHLs and this indicates that the high- grade NHL display a higher proliferation rate than low grade. In addition, remarkable variations in MIB1 expression were found among individual cases of the same histological group. These data may suggest that MIB1 index can help in the individual approach of the proliferation rate of each tumour and this may be an important parameter in association with clinical and other laboratory parameters for predicting the biological behaviour of non-Hodgkin's lymphomas.

p53 protein expression in non-Hodgkin's lymphoma. Comparative study with the wild type p53 induced proteins mdm2 and p21/waf1.

Aims-To investigate the pattern of expression of p53 protein and two wild type p53 induced proteins (mdm2 and p21/waf1) as an indirect way of assessing p53 gene status in non-Hodgkin's lymphoma.Methods-Formalin fixed, paraffin wax embedded tissue from 87 cases of nodal non-Hodgkin's lymphoma, comprising 52 high grade and 35 low grade tumours, was stained by immunohistochemistry for p53, mdm2 and p21/waf1 proteins.Results-p53, mdm2 and waf1/p21 proteins were expressed in 36/52, 21/52 and 31/52 high grade and 3/35, 21/35 and 3/35 low grade non-Hodgkin's lymphomas, respectively. Parallel p53/mdm2 protein expression was found in 23 cases (21 high grade and two low grade). These 23 cases were also positive for p21/waf1 protein expression. Discordant p53 positive/mdm2 negative protein expression was found in 16 cases (15 high grade and one low grade). Eleven (10 high grade and one low grade) of these 16 cases were p21/waf1 positive and the remaining five high grade non-Hodgkin's lymphomas were p21/waf1 negative. Mdm2 and p21/waf1 proteins were not expressed in the absence of p53 protein expression.Conclusions-p53, mdm2 and waf1/p21 protein expression is more frequently associated with aggressive histotypes of non-Hodgkin's lymphoma. Parallel expression of p53, mdm2 and p21 proteins may represent non-Hodgkin's lymphomas with a wild type p53 gene as mdm2 and p21 proteins can be induced by the wild type gene. In these cases p53 protein expression may result from stabilisation via complex formation with the mdm2 protein. This could be important in the pathogenesis of these cases as mdm2 may deregulate the p53 dependent growth suppressive pathway. Discordant p53 positive/mdm2 negative/p21 negative protein expression may represent non-Hodgkin's lymphoma with p53 gene mutations unable to activate expression of mdm2 and p21 proteins. Non-Hodgkin's lymphoma with p53 positive/mdm2 negative/p21 positive protein expression may have either wild type p53 with deregulated mdm2 gene expression or mutated p53 gene with p53 independent p21 expression.

Expression of p53 and mdm-2 proteins in Hodgkin's Disease. Absence of correlation with the presence of Epstein-Barr virus.

The expression of p53 and mdm-2 proteins was analysed in parrafin sections from 39 cases of Hodgkin's disease (HD) and compared to the presence of Epstein-Barr Virus (EBV). P53 protein was found in Hodgkin and Reed-Sternberg (HRS) cells in 12/39 cases. Mdm-2 protein was found in HRS cells in 10/39 cases. EBV-encoded EBER1-2 mRNAs and LMP-1 protein expression were found in HRS cells in 16/39 cases. In view of the LMP-1 oncogenic potential in vitro, these findings suggest that EBV may be involved in the pathogenesis of a proportion of HD cases. The coexpression of mdm-2 and p53 proteins was found in HRS cells in 10 cases, whereas in 27 cases neither was identified and in 2 cases there was no coexpression of mdm-2/p53. The simultaneous p53/mdm-2 protein expression, in view of previous findings which showed that most cases of HD display no p53 gene mutations, suggests that mdm-2 protein expression may be one of the factors responsible for the stabilisation of p53 protein in these cases. This could be important, in the pathogenesis of these cases of HD, since mdm-2 may deregulate the p53 dependent growth suppressive pathway. Mdm-2-/ p53+ protein expression may reflect the stabilisation of p53 protein by proteins other than mdm-2, mutations in the p53 gene making it unable to activate mdm-2, or the deregulation of the mdm-2 gene. No relationship was found between the presence of EBV and the expression of p53 and/or mdm-2 proteins.

Congenital ectopic vas deferens inserting into the bladder with ipsilateral renal agenesis.

Vas deferens ectopia is a rare congenital anomaly which is frequently associated with anorectal abnormalities. There have been 20 cases up to date with an ectopic vas deferens inserting into the ureter. Out of these 6 had a bilateral insertion and another 4 cases with an ectopic vas deferens inserting directly into the bladder, out of which 1 had a bilateral insertion. There is an embryological hypothesis which may explain this rare condition that may result from a possible underlying defect of the proximal vas precursor segment of the Wolffian duct. Herein, we present a case of an ectopic vas deferens terminating in the urinary bladder and accompanied by ipsilateral renal agenesis. This is the second case report in the world literature.