A new case of malignant mesothelioma of the tunica vaginalis testis. Immunohistochemistry in comparison with an adenomatoid tumor of the testis

Our plain-English summary of A new case of malignant mesothelioma of the tunica vaginalis testis. Immunohistochemistry in comparison with an adenomatoid tumor of the testis, by H. Moch, H. Ohnacker, R. Epper, et al (Pathology, Research and Practice, 1994).

The study

• Authors: H. Moch, H. Ohnacker, R. Epper, F. Gudat, M.J. Mihatsch
• Journal: Pathology, Research and Practice
• Published: 1994;190(4):400-4; discussion 404-8
• Type of article: Case report, Review
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Malignant mesothelioma of the tunica vaginalis testis is an extremely rare tumor with 41 previously reported cases. The histological and immunohistological features of a new case in an 80-year-old patient are described and compared with an adenomatoid tumor of the tunica vaginalis testis, which is considered to be the benign variant of malignant mesothelioma. Both tumors revealed strong cytoplasmic staining for a panepithelial antibody (Lu-5) and membranous staining for BMA-120 (a mesothelial/endothelial cell marker) but yielded negative staining results with the endothelial cell markers QBend-10 (CD 34), Factor VIII-related antigen (vWF) and UEA-1. There was also negative staining for CEA, Ber-EP4, HEA-125 and Blood group related antigens A, B, H. An identical staining pattern was evident in normal and reactive mesothelial cells. Our data support a mesothelial rather than an endothelial derivation of the adenomatoid tumor studied.

In plain English

This teaching case report from Basel, Switzerland, described malignant mesothelioma of the tunica vaginalis testis (the lining around the testis) in an 80-year-old man. It compared the tumor's staining with one adenomatoid tumor of the testis, which the authors said is considered the benign variant of malignant mesothelioma. The man had a one-month history of painless right-sided scrotal swelling and had had a hydrocele operation three years earlier. Examination of the removed right testis unexpectedly showed malignant mesothelioma. It had invaded tissue under the mesothelium and vessels in the spermatic cord, but not the testis or epididymis. He had no history of asbestos exposure. He received no further treatment and was well and free of relapse 25 months later. The tumor stained for the markers Lu-5 and BMA-120. It did not stain for three endothelial markers or for CEA, vimentin, HEA-125, Leu-M1, blood group antigens A, B, H or Ber-EP4. The adenomatoid tumor showed a comparable pattern, with weak vimentin staining. The authors concluded that their data supported a mesothelial origin of the adenomatoid tumor studied.

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 report (teaching case) of one malignant mesothelioma, with immunohistochemical comparison to one adenomatoid tumor of the testis
• Who was studied: One 80-year-old man with malignant mesothelioma of the tunica vaginalis testis (Institute of Pathology, Basel University, Switzerland), plus one adenomatoid tumor of the testis used for comparison
• Exposure: No asbestos exposure was reported. The patient had no history of asbestos exposure or of recent trauma to the testicles. He had a hydrocelectomy three years earlier and a small recurrent hydrocele two years later.
• Main results:
  • In the patient, the histopathological examination of the removed right testis unexpectedly showed a malignant mesothelioma.
  • The patient's tumor had glandular and papillary structures and had invaded the connective tissue under the mesothelium. Vascular invasion was seen in the spermatic cord.
  • In the patient, the testis and epididymis were not invaded by the tumor.
  • The mesothelioma cells stained strongly in the cytoplasm for Lu-5, and all tumor cells showed membranous staining for BMA-120.
  • The mesothelioma cells did not stain for CEA, vimentin, HEA-125, Leu-M1, blood group antigens A, B, H or Ber-EP4.
  • The endothelial markers Factor VIII (vWF), UEA-1 and QBend-10 stained only endothelial cells, not the mesothelioma cells.
  • The comparison adenomatoid tumor showed a comparable staining pattern, but with weak reactivity for vimentin.
  • In this case, BMA-120 stained endothelial cells as well as normal and neoplastic mesothelial cells.
  • The patient received no additional therapy because of his age and was well and free of relapse 25 months later.
• The authors' conclusion: The authors concluded that their data support a mesothelial, rather than endothelial, origin of the adenomatoid tumor studied. They also wrote that immunohistochemistry could help distinguish mesotheliomas of the tunica vaginalis testis from metastatic adenocarcinomas or rete testis adenocarcinomas.

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, Tunica Vaginalis, Immunohistochemistry, Adenomatoid Tumor, Ber-EP4, Reactive Mesothelial Hyperplasia.

Related studies

• Adenomatoid tumors in the tunica albuginea of the testis — J.A. Arcadi (1988)
• Rare tumors of the testis and mesothelial proliferation in the tunica vaginalis — M. Colecchia, G. Mikuz, et al. (2012)
• Mesothelioma of the tunica vaginalis testis: report of 2 cases with asbestos occupational exposure — G. Gorini, M. Pinelli, et al. (2005)
• Cutaneous Metastases From Malignant Mesothelioma of the Tunica Vaginalis Testis — P. Hispán, J.C. Pascual, et al. (2016)
• Malignant mesothelioma of the tunica vaginalis testis: diagnostic studies and differential diagnosis — S.S. Chekol, C.C. Sun (2012)
• Papillary serous carcinoma of the tunica vaginalis testis — P. Becerra, M.A. Isaac, et al. (2000)

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