Mesothelioma of tunica vaginalis of "uncertain malignant potential" - an evolving concept: case report and review of the literature

Our plain-English summary of Mesothelioma of tunica vaginalis of "uncertain malignant potential" - an evolving concept: case report and review of the literature, by K. Trpkov, R. Barr, A. Kulaga, et al (Diagnostic Pathology, 2011).

The study

• Authors: K. Trpkov, R. Barr, A. Kulaga, A. Yilmaz
• Journal: Diagnostic Pathology
• Published: 2011;6:78
• Type of article: Case report, Review
• Cited by: 22 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Mesothelioma of tunica vaginalis is a rare neoplasm, typically demonstrating frankly malignant morphology and aggressive behavior. Rare cases of well-differentiated papillary mesotheliomas have also been reported, which, in contrast, demonstrate indolent behavior. There are, however, cases which do not fit into the well-differentiated or diffuse malignant mesothelioma categories and can be considered mesothelioma of tunica vaginalis of "uncertain malignant potential", which is an emerging diagnostic category. A 57-year-old man presented with a neoplasm in a hydrocele sac. The neoplasm was non-invasive, but showed focal complex and solid growth and it was difficult to categorize either as well-differentiated papillary mesotheliomas or malignant mesothelioma. After the initial limited resection, the patient underwent radical orchiectomy with hemiscrotectomy and is alive and without disease progression after 6 years. Documentation of these rare tumors will allow their distinction from true malignant mesotheliomas and will facilitate the development of specific treatment recommendations.

In plain English

This article was a case report combined with a review of the medical literature. It described a 57-year-old man who had a hydrocele (fluid around the testis) for 6 months before routine surgery. No prior history of local trauma or asbestos exposure was documented. During surgery, two small nodules measuring 1.5 cm and 0.5 cm were found on the tunica vaginalis, the lining around the testis, and were removed. Under the microscope the tumor was mostly papillary with bland cells, but it had focal complex and solid areas. No invasion was found, although little surrounding tissue had been removed. Because malignant mesothelioma could not be ruled out, his testis and part of the scrotum were removed five months later. No remaining tumor was found, and after 6 years there was no disease progression. The authors' literature review found only 9 well-documented cases of well-differentiated papillary mesothelioma of the tunica vaginalis. The authors concluded that this tumor can be considered a mesothelioma of "uncertain malignant potential" and that the right treatment for such cases is uncertain.

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 with review of the literature
• Who was studied: one 57-year-old man with a hydrocele; the authors are based in Calgary, Alberta, Canada
• Exposure: no prior history of asbestos exposure (or local trauma) was documented for this patient
• Main results:
  • Two small pedunculated nodules, 1.5 cm and 0.5 cm in diameter, arose from the tunica vaginalis above the head of the epididymis, with no gross evidence of invasion; they were removed by limited local resection
  • Under the microscope the nodules were mostly papillary with bland nuclei and no more than mild atypia, but parts showed more complex trabecular, syncitial and solid growth
  • A single microfocus of coagulative necrosis was seen, and only one mitotic figure was found on complete sampling (less than 1 mitosis per 50 high-power fields)
  • On immunohistochemistry the tumor cells were positive for cytokeratin, calretinin, D2-40, WT-1 and vimentin, were focally positive for EMA and p53 (about 10-20% of tumor cells), and Ki-67 was positive in less than 1% of cells
  • Radical orchiectomy with hemiscrotectomy, done five months after the first resection, showed no residual neoplasm; only three surface micronodules of reactive mesothelial hyperplasia were found
  • After 6 years of follow-up the patient had no disease progression and no evidence of local recurrence or metastatic disease
  • The authors' literature review found only 9 well-documented cases of well-differentiated papillary mesothelioma (WDPM) of the tunica vaginalis since 1957, in men aged 18 to 70 years (median 56), all with a good outcome
• The authors' conclusion: The authors concluded that the tumor can be considered a mesothelioma of tunica vaginalis of uncertain malignant potential, which is an emerging category for cases that fit neither WDPM nor diffuse malignant mesothelioma. They added that the appropriate treatment for such cases is uncertain and that long-term follow-up needs to be documented.
• Limitations the authors state:
  • Only limited stroma was removed at the edge of the nodules, so the assessment of invasion rested on limited tissue
  • In the reviewed WDPM cases, follow-up was relatively short: up to 3 years for 7 of 8 patients with available follow-up

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, Neoplasm, Well-Differentiated Papillary Mesothelioma, Well-Differentiated, Hydrocele, Orchiectomy, Hemiscrotectomy.

Related studies

• Mesothelioma of the tunica vaginalis: a series of eight cases with uncertain malignant potential — F. Brimo, P.B. Illei, et al. (2010)
• Malignant mesothelioma of the tunica vaginalis testis: a rare case and review of literature — M. Drevinskaite, A. Patasius, et al. (2020)
• Malignant Mesothelioma of the Tunica Vaginalis Testis-A Malignancy Associated With Asbestos Exposure and Trauma: A Case Report and Literature Review — A.A. Baqui, N.A. Boire, et al. (2019)
• Malignant mesothelioma of tunica vaginalis testis: Report of a very rare case with review of the literature — E. Trenti, S.M. Palermo, et al. (2018)
• Mesothelioma of the tunica vaginalis testis: a rare malignancy mimicking more common inguino-scrotal masses — P.J. Schure, K.C. van Dalen, et al. (2006)
• Malignant mesothelioma of the tunica vaginalis testis: report of first case with preoperative diagnosis — L. Japko, A.A. Horta, et al. (1982)

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