Mesothelioma of the testis: histopathological examination essential for classification

Mesotheliomas are very aggressive tumours, almost exclusively caused by asbestos, which are very often occupational. Between 2014 and 2020, four out of five cases of testicular mesothelioma assessed at an institute were recognised as occupational diseases. The fifth case could not be classified due to lack of involvement of the affected person. However, all five cases were initially treated under a suspected diagnosis that was not related to mesothelioma of the testis. This shows the importance of histopathological examination of the surgically removed tissue.

Quelle: IDW Informationsdienst Wissenschaft

Drug combination shows meaningful responses for malignant peritoneal mesothelioma patient

A phase II study found that treatment with atezolizumab and bevacizumab was well-tolerated and resulted in a 40% objective response rate in patients with advanced malignant peritoneal mesothelioma, a rare cancer in the lining of the abdomen.

Quelle: Sciencedaily

The carcinogenic effect of various multi-walled carbon nanotubes (MWCNTs) after intraperitoneal injection in rats

Non-neoplastic histopathological findings in the abdominal cavity. A: High-power view of anti-podoplanin immunohistochemistry showing single MWCNT A (high dose) nanotubes in the tissue (arrows). B: High-power view of anti-podoplanin immunohistochemistry showing single asbestos fibers in the tissue (arrows). C: H & E, high-power view of granuloma induced by MWCNT A (low dose) nanotubes including single nanotube (arrow, 25×). D: H & E, high-power view of granuloma induced by asbestos including single fiber (arrow, 40×). Rittinghausen et al. Particle and Fibre Toxicology 2014 11:59   doi:10.1186/s12989-014-0059-z
Non-neoplastic histopathological findings in the abdominal cavity. A: High-power view of anti-podoplanin immunohistochemistry showing single MWCNT A (high dose) nanotubes in the tissue (arrows). B: High-power view of anti-podoplanin immunohistochemistry showing single asbestos fibers in the tissue (arrows). C: H & E, high-power view of granuloma induced by MWCNT A (low dose) nanotubes including single nanotube (arrow, 25×). D: H & E, high-power view of granuloma induced by asbestos including single fiber (arrow, 40×).
Rittinghausen et al. Particle and Fibre Toxicology 2014 11:59 doi:10.1186/s12989-014-0059-z

Susanne Rittinghausen, Anja Hackbarth, Otto Creutzenberg, Heinrich Ernst, Uwe Heinrich, Albrecht Leonhardt and Dirk Schaudien

Abstract

Background

Biological effects of tailor-made multi-walled carbon nanotubes (MWCNTs) without functionalization were investigated in vivo in a two-year carcinogenicity study. In the past, intraperitoneal carcinogenicity studies in rats using biopersistent granular dusts had always been negative, whereas a number of such studies with different asbestos fibers had shown tumor induction. The aim of this study was to identify possible carcinogenic effects of MWCNTs. We compared induced tumors with asbestos-induced mesotheliomas and evaluated their relevance for humans by immunohistochemical methods.

Methods

A total of 500 male Wistar rats (50 per group) were treated once by intraperitoneal injection with 109 or 5 × 109 WHO carbon nanotubes of one of four different MWCNTs suspended in artificial lung medium, which was also used as negative control. Amosite asbestos (108 WHO fibers) served as positive control. Morbid rats were sacrificed and necropsy comprising all organs was performed. Histopathological classification of tumors and, additionally, immunohistochemistry were conducted for podoplanin, pan-cytokeratin, and vimentin to compare induced tumors with malignant mesotheliomas occurring in humans.

Results

Treatments induced tumors in all dose groups, but incidences and times to tumor differed between groups. Most tumors were histologically and immunohistochemically classified as malignant mesotheliomas, revealing a predominantly superficial spread on the serosal surface of the abdominal cavity. Furthermore, most tumors showed invasion of peritoneal organs, especially the diaphragm. All tested MWCNT types caused mesotheliomas. We observed highest frequencies and earliest appearances after treatment with the rather straight MWCNT types A and B. In the MWCNT C groups, first appearances of morbid mesothelioma-bearing rats were only slightly later. Later during the two-year study, we found mesotheliomas also in rats treated with MWCNT D – the most curved type of nanotubes. Malignant mesotheliomas induced by intraperitoneal injection of different MWCNTs and of asbestos were histopathologically and immunohistochemically similar, also compared with mesotheliomas in man, suggesting similar pathogenesis.

Conclusion

We showed a carcinogenic effect for all tested MWCNTs. Besides aspect ratio, curvature seems to be an important parameter influencing the carcinogenicity of MWCNTs.

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