Expression of bcl-2 protein in nephroblastomas

Bcl-2 expression has been shown to relate to prognosis in several neoplasms. A study of 139 cases of nephroblastomas was undertaken to ascertain the prognostic value of bcl-2 immunoexpression. Archival formalin-fixed, paraffin-embedded tissue sections were stained with monoclonal anti-bcl-2 antibody using a peroxidase-labelled streptavidin biotin kit. 75.5% of cases showed bcl-2 immunoreactivity, however, heterogeneous staining was observed within each case. No statistically significant correlation was found when bcl-2 expression was compared to histology (P=0.451), disease status (P=0.375) and disease stage (P=0.875). A statistically significant difference in bcl-2 protein was noted when comparing tumours treated with and those not treated with pre-operative chemotherapy (P=0.002). Further analysis of the cases that were treated with pre-operative chemotherapy showed a striking difference in survival periods between bcl-2 positive (shorter) and negative tumours (longer). Although not statistically significant, we think that this finding requires further investigation in other series. The results of bcl-2 immunoexpression in nephroblastomas may have prognostic implications that impact on patient treatment protocols.

Large cell neuroendocrine carcinoma of the thymus

AIM

We highlight the occurrence of an unusual neuroendocrine tumour, a large cell neuroendocrine carcinoma, arising from the thymus.

CASE DETAILS

A 68-year-old man with a history of cigarette smoking had a large mediastinal tumour arising from the thymus removed. Two years later the tumour recurred; it was debulked surgically but the patient died 2 months later: Histological examination of both tumour specimens revealed a tumour with an endocrine pattern, composed of large pleomorphic cells with large nuclei and prominent nucleoli. The mitotic count ranged from 19 to 26 per 10 high-power fields and large tracks of coagulative tumour necrosis were present. The tumour cells were strongly positive for neuron-specific enolase (NSE), chromogranin, CAM5.2 and AE1/3, with cytoplasmic dot-like accentuation for the latter three markers. The tumour fulfilled the criteria for a diagnosis of large cell neuroendocrine carcinoma.

CONCLUSIONS

Large cell neuroendocrine carcinoma should be distinguished from atypical carcinoid and small cell carcinoma. It is a distinctive neuroendocrine malignancy with a prognosis between that of atypical carcinoid and small cell carcinoma, and needs to be treated aggressively.

Inflammatory pseudotumor of the breast

Inflammatory pseudotumors (IP) have come to the forefront in recent times with this characteristic lesion being described in several sites. The multiplicity of sites of occurrence is matched by the plethora of names given to this condition. It has been rejoiced under the rubric of plasma cell granuloma, xanthomatous pseudotumor, xanthogranuloma, inflammatory myofibroblastic tumor/lesion and inflammatory fibromyxoid tumor, to name but some. This paper presents three cases of IP occurring in the breast and highlights the histological features in this unusual site.

CD31 (JC70) expression in plasma cells: an immunohistochemical analysis of reactive and neoplastic plasma cells

AIMS

To investigate the immunohistochemical expression of CD31 (JC70) in normal and neoplastic plasma cells.

METHODS

Plasma cells in bone marrow biopsies and extramedullary locations were examined. All extramedullary biopsies were formalin fixed and paraffin embedded. The bone marrow biopsies were fixed in formal acetic acid and embedded in paraffin wax. Twenty multiple myelomas (12 bone marrow and eight extramedullary deposits), 10 extramedullary plasmacytomas, and 30 biopsies with reactive plasma cells (10 bone marrow, 20 extramedullary biopsies) were stained with anti-CD31 (JC70) using the streptavidin-biotin detection system with diaminobenzidine as a chromogen. Antigen retrieval in bone marrow biopsies was achieved by pressure cooking. In all other biopsies, antigen retrieval was achieved by microwave pretreatment.

RESULTS

All 20 extramedullary cases with reactive plasma cells showed intense membrane staining. Focal staining was detected in reactive plasma cells in bone marrow biopsies. Five of 10 plasmacytomas showed membrane staining. None of the cases of multiple myeloma, either medullary or extramedullary, showed any immunoreactivity for CD31.

CONCLUSIONS

CD31, a member of the immunoglobulin supergene family of cell adhesion molecules, is strongly expressed in extramedullary reactive plasma cells, focally in bone marrow reactive plasma cells, and occasionally in extramedullary plasmacytomas.

Mucosal prolapse changes in Hirschsprung's disease

The aim of this study was to ascertain the incidence of mucosal prolapse changes in Hirschsprung's disease. Twenty-three random, consecutive resection specimens for this condition were analysed for the histological features of prolapse. Eight cases showed histological evidence suggesting mucosal prolapse at the junction between ganglionic and aganglionic bowel. Thickening and splaying of the muscularis mucosae with extension into the lamina propria, and the presence of metaplastic or hyperplastic tubules with goblet cell and cryptal hypertrophy were the dominant histological features found in the eight cases. In addition, an increase in elastic fibres in the lamina propria and diamond-shaped glands were seen to varying degrees in all eight cases. Mucosal prolapse was more prominent in the older patients and is, therefore, related to duration of symptoms. Differential pressures in ganglionic and aganglionic segments of bowel, together with faecal stream and straining are likely to be of pathogenetic significance.

Inflammatory pseudotumour and Rosai-Dorfman disease of soft tissue: a histological continuum?

A lesion of the chest wall in a 34 year old woman, which had a combination of histological and immunophenotypic features of inflammatory pseudotumor and Rosai-Dorfman disease of soft tissue, is described. There was considerable overlap in the pathogenesis, histology and immunophenotype of these two lesions. The similarities between these two lesions suggest that there is a temporal sequence and a histological continuum with early histiocyte-rich and late fibroblast- and myofibroblast-rich lesions. Alternatively, the morphological and immunophenotypic features could be because of aberrant cytokine expression in an inflammatory pseudotumour, resulting in transformation of histiocytes to resemble those seen in Rosai-Dorfman disease.

Advances in protein-based three-dimensional optical memories

An oriented bacteriorhodopsin cube is optimized as a potential three-dimensional optical memory medium. Write/read capability is demonstrated by using the photovoltaic signal induced by two-photon absorption. Our results demonstrate that a two-photon induced photovoltage can he detected in a three-dimensional Bacteriorhodopsin (BR) cube as large as 1.6 x 1.6 x 1.6 cm3. The read/write speed, signal to noise ratio, and the laser damage threshold for the protein-based three-dimensional optical memory is examined.

Adenomatous hyperplasia of the rete testis in the undescended testis

Multiple foci of micronodular or tubulopapillary structures were noted in the rete testis of 13 cases of undescended testes. These structures were lined by low columnar to cuboidal epithelium, showed back-to-back crowding, and were supported by a thin lamina propria. These changes, referred to as adenomatous hyperplasia of the rete testis, appear to be a frequent finding in the undescended testis. An age-matched control group did not show any of these features.