Mesothelioma with rhabdoid features: an ultrastructural and immunohistochemical study of 10 cases

Our plain-English summary of Mesothelioma with rhabdoid features: an ultrastructural and immunohistochemical study of 10 cases, by N.G. Ordóñez (Modern Pathology, 2006).

The study

• Author: N.G. Ordóñez
• Journal: Modern Pathology
• Published: 2006;19(3):373-83
• Cited by: 45 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Mesotheliomas with rhabdoid morphology are rare and only two individual case reports have been documented in the literature. This author reports a series of 10 cases of mesotheliomas with rhabdoid features, nine of which originated in the pleura and one in the peritoneum. Eight of the patients were men and two were women. Six patients had a history of asbestos exposure. Histologically, seven of the mesotheliomas were epithelioid, two sarcomatoid, and one biphasic. The proportion of the rhabdoid cells seen in these cases constituted 15-75% of the individual tumors. Cytoplasmic staining in the rhabdoid cells was seen for pan-keratin and vimentin in all 10 cases, for keratin 7 in eight of eight, for calretinin in nine of 10, and for keratin 5/6 in seven of nine. Nuclear positivity for WT1 was observed in the rhabdoid cells of four of seven cases and membranous reactivity for mesothelin in four of six, and for podoplanin in two of six. Only one case showed desmin positivity in sparse cells in the nonrhabdoid component of the tumor. All of the cases were negative for CEA, MOC-31, TAG-72, CD15, CD34, bcl2, muscle-specific actin, and TTF-1. Ultrastructural studies revealed paranuclear collections of intermediate filaments, but no evidence of rhabdomyoblastic differentiation was seen. The mean survival of five of the six patients for whom this information was available was 3.8 months. The remaining patient had a survival time of 1 year. It is important for pathologists to be aware that mesotheliomas can present rhabdoid features, not only because they can be confused with other malignancies that can exhibit a similar morphology, but also because of their apparently unusually aggressive behavior. The value of immunohistochemistry and electron microscopy in the differential diagnosis of these tumors is discussed.

In plain English

This was a case series in which the author described 10 mesotheliomas with rhabdoid features. These are cells with abundant cytoplasm, an off-center nucleus and a rounded inclusion in the cytoplasm. The cases came from the files of the University of Texas MD Anderson Cancer Center and the author's personal consultation files. Eight patients were men and two were women, aged 52 to 79 years. Six had a history of asbestos exposure; the article did not name fiber types. Nine tumors arose in the pleura and one in the peritoneum. Seven were epithelioid, two sarcomatoid and one biphasic, and rhabdoid cells made up 15 to 75% of the individual tumors. The rhabdoid cells stained for vimentin and pan-keratin in all 10 cases and for calretinin in nine of 10. Electron microscopy showed collections of intermediate filaments beside the nucleus, and no evidence of rhabdomyoblastic differentiation was seen. All six patients with follow-up died of disease 3 to 12 months after diagnosis. The author concluded that the tumors apparently behave unusually aggressively, and said that studies with larger numbers of cases are needed.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case series: an ultrastructural (electron microscopy) and immunohistochemical study of 10 cases
• Who was studied: 10 patients with mesothelioma with rhabdoid features, from the files of the Department of Pathology and Electron Microscopy section at the University of Texas MD Anderson Cancer Center (Houston) and the author's personal consultation files. There were 8 men and 2 women, aged 52 to 79 years (mean 62.8). Nine tumors were pleural and one peritoneal. Dates of diagnosis were not given.
• Exposure: A history of asbestos exposure was reported in 6 of the 10 patients and smoking in 3. Fiber types, products, jobs and doses were not reported.
• Main results:
  • Of the 10 mesotheliomas, nine originated in the pleura and one in the peritoneum.
  • Of the 10 mesotheliomas, seven were epithelioid, two sarcomatoid and one biphasic. The rhabdoid component ranged from 15 to 75% of the individual tumors.
  • The rhabdoid cells in all 10 cases reacted strongly for vimentin and pan-keratin.
  • Keratin 7 was expressed in all eight cases stained for this marker.
  • The rhabdoid cells stained for calretinin in nine of 10 cases and for keratin 5/6 in seven of nine.
  • The rhabdoid cells showed nuclear WT1 positivity in four of seven cases, membranous mesothelin reactivity in four of six, and podoplanin reactivity in two of six.
  • Only one case showed focal desmin positivity, and it was in the nonrhabdoid cells. Eight cases were tested for desmin.
  • No case stained for muscle-specific actin, bcl-2, CD15, CD34, TAG-72, CEA, MOC-31 or TTF-1 was positive, in either the rhabdoid or the nonrhabdoid parts of the tumors.
  • Electron microscopy, done in nine cases, showed rhabdoid cells with abundant cytoplasm containing collections of intermediate filaments beside the nucleus. No evidence of rhabdomyoblastic differentiation was seen.
  • In two cases (cases 7 and 8), several peribronchial lymph nodes were involved by metastases.
  • All six patients with follow-up information died of disease 3 to 12 months after diagnosis. The Results section gives the mean as 5.7 months.
  • Among those six patients, one survived 1 year after diagnosis. The other five died within 6 months, with a mean survival of 3.8 months.
• The authors' conclusion: The author concluded that pathologists should be aware that mesotheliomas can present rhabdoid features. Such tumors can be confused with other malignancies of similar appearance, and they apparently behave unusually aggressively.
• Limitations the authors state:
  • The author stated that more studies with larger numbers of cases are needed to fully determine the prognostic significance of the rhabdoid phenotype in mesotheliomas.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Rhabdoid, Pleura, Peritoneum, Asbestos Exposure, Epithelioid, Sarcomatoid, Biphasic Mesothelioma.

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• Concurrent occurrence of renal cell carcinoma with rhabdoid features in a married couple: a case report — R. Matsumoto, N. Shinohara, et al. (2015)
• Immunohistochemical analysis still has a limited role in the diagnosis of malignant mesothelioma. A study of thirteen antibodies — F. Roberts, C.M. Harper, et al. (2001)
• Two cases of malignant peritoneal mesothelioma without asbestos exposure: cytologic and immunohistochemical features — Y. Kinoshita, K. Takasu, et al. (2013)
• Giant Pediatric Rhabdoid Meningioma Associated with a Germline BAP1 Pathogenic Variation: A Rare Clinical Case — A.C. Ravanpay, A. Barkley, et al. (2018)

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