Search

The formation of true synovial-lined membranes at tissue sites not intimately related to an articulation or a tendon sheath has been described in a variety of pathologic and postsurgical conditions, but until recently has not been well recognized to occur in association with tissue surrounding silicone breast implants. Of 15 cases with resected periprosthetic breast capsules, 7 (47%) demonstrated true synovial metaplasia with capsule-implant interfaces lined by typical synovial cells. Histochemical and immunohistochemical staining reactions were essentially identical to those observed in synovial control cases and featured positive reactions to Alcian blue-periodic acid-Schiff, reticulin, and vimentin. Focal positive immunoreactivity was observed with alpha 1-antitrypsin, alpha 1-antichromotrypsin, lysozyme, and CD68. No immunoreactivity was observed with cytokeratin AE1/AE3, S-100 protein, carcinoembryonic antigen, or basement membrane antigens. Transmission electron microscopy of the lining cells confirmed their true synovial nature with the type A (macrophage-like) cells, type B (fibroblast-like) cells, and intermediate forms or type AB cells identified. We conclude that the cellular lining surrounding silicone breast implants is a true synovial membrane, that synovial metaplasia may occur in nearly one half of all resected periprosthetic capsules, and that awareness of this entity will enable the surgical pathologist to render an accurate histopathologic diagnosis.

A case of intracranial malignant peripheral nerve sheath tumor (MPNST) with uncommon features due to recurrence is reported. The primary tumor showed typical histopathological features of MPNST with wavy nuclei and S-100 positivity. The patient's latest recurrent tumor resembled undifferentiated sarcoma with lipoblast-like multivacuolated cells and hyaline globules (HGs). Ultrastructurally, the vacuolated spaces contained granular materials derived from cystic dilation of the rough endoplasmic reticulum. The HG consisted of round osmophilic inclusions with or without a limiting membrane. The HGs and lipoblast-like multivacuolated cells may have been caused by the degeneration of tumor cells in myxoid stroma and abundant vasculature. [ABSTRACT FROM AUTHOR]

The cell adhesion molecules (CAMs) CD44 standard (CD44s) and its variant 6 (CD44v6) are involved in the progression and invasion of human malignancies. However, discrepancies in the prognostic value of CD44s and CD44v6 expression need to be addressed. Aims: To investigate the expression of CD44s and CD44v6 in bladder carcinomas and relate the results to the established prognostic factors. Materials and Methods: 50 bladder carcinoma specimens, 30 cases with transitional cell carcinoma (TCC: 6 bilharzial and 24 nonbilharzial) and 20 cases with squamous cell carcinoma (SCC: 8 bilharzial and 12 nonbilharzial), were included. Immunohistochemical analysis for CD44s and CD44v6 was carried out using avidin-biotin peroxidase method. Results: The level of both CD44s and CD44v6 in TCC was significantly higher in invasive than in preinvasive tumors and normal urothelium ( p < .05). A direct association between the percentage of expression of both markers and the grade of TCC ( p < .05) was observed. An inverse correlation between CD44s and SCC was seen, where metaplastic urothelium showed higher expression than invasive carcinomas. No association was observed between the expressions of both CD44s and CD44v6 and bilharzial ova, sex and age of the patient, or size of the tumor. Conclusions: The authors report statistically significant correlation between CD44s and CD44v6 expression and increasing grade and stage of TCC. No such correlation with SCC and with bilharzial cystitis, sex and age of the patient, or size of the tumor was documented. [ABSTRACT FROM AUTHOR]

Apoptosis is the distinctive form of programmed cell death that complements cell proliferation in maintaining normal tissue homeostasis. The significance of constitutive apoptosis in the recurrence of Non Muscle Invasive Bladder Cancer has yet to be investigated. The aim of this study is to investigate the prognostic significance of Bax and Bcl-2 in terms of recurrence after BCG immunotherapy. Immunohistochemical analysis was performed on frozen biopsies to evaluate bcl-2 and Bax proteins expression in 28 cases of NMIBC. All patients with confirmed NMIBC were treated with intravesical BCG-immunotherapy. The follow up was performed for 26 months. The correlation between clinicopathological, immunohistochemical data and the response to BCG therapy was performed. Univariate analysis showed that, PT1 stage, High grade and Bax expression increased significantly the risk of recurrence (P == 0.015, P == 0.015 and P== 0.034 respectively). In addition, multivariate analysis selected the model involving stage, age, Bax and Bcl-2 expression as the best independent variables of recurrence. In conclusion, the expression of Bcl-2 and Bax in NMIBC could have a prognostic value in assessing the risk of recurrence after BCG immunotherapy. These findings require further investigations on larger cohort in order to ascertain new molecular markers of the response to BCG immunotherapy. [ABSTRACT FROM AUTHOR]

Angiomyolipoma (AML) is a mesenchymal neoplasm of unclear histogenesis. In addition to varying amounts of smooth muscle, adipose tissue, and blood vessels, it contains a population of clear or pale eosinophilic epithelioid cells often arranged around blood vessels. Various phenotypes of AML have been described: leiomyoma-like, lipoma-like, epithelioid, and atypical. AMLs show consistent immunopositivity for HMB-45. This has been associated with the ultrastructural observation of melanosome-like structures in rare instances. In the present study, 14 AMLs from 13 patients were analyzed by electron microscopy and immunohistochemistry to determine the appearance and nature of cells composing AMLs. Overlap between cell types (spindle smooth muscle cells, epithelioid cells, and adipocytes) was found by both electron microscopy and immunohistochemistry. Melanosomes were found in 7 tumors. The cell of origin remains mysterious. Nevertheless, the study demonstrates that the AML is likely derived from a single cell that shares homology with the pericyte. [ABSTRACT FROM AUTHOR]