Well-differentiated papillary mesothelioma of the tunica vaginalis: A case report with aspirate cytologic, immunohistochemical, and ultrastructural studies

Department of Pathology, The Jikei Daisan Hospital, The Jikei University School of Medicine, 4-11-1, Izumihoncho, Komaeshi, Tokyo 201-8601, Japan.
Pathology - Research and Practice (Impact Factor: 1.4). 04/2009; 206(2):105-9. DOI: 10.1016/j.prp.2009.02.006
Source: PubMed


A case of a well-differentiated papillary mesothelioma of the tunica vaginalis testis in a 70-year-old man, who presented with a 1-month history of scrotal swelling with hydrocele, is described. Fine needle aspiration cytology of the hydrocele demonstrated a papillary cluster of uniform round cells with minimal atypia, reminiscent of mesothelial cells. Macroscopically, the lesion was characterized by a solitary, well-circumscribed papillary soft tumor measuring 1.2 x 1.2 x 1.0 cm(3). Histologically, the tumor exhibited papillary or tubulopapillary proliferation of predominantly bland cuboidal cells. No cellular pleomorphism, mitotic figures, necrosis, or stromal invasion was noted. Immunohistochemically, the tumor was positive for CAM5.2, epithelial membrane antigen, vimentin, calretinin, and D2-40, but negative for carcinoembryonic antigen. Ki-67 index was less than 1%. Ultrastructurally, the tumor cells showed numerous microvilli, mitochondria, rough endoplasmic reticulum, microfilaments, and desmosomes. The patient is alive with no evidence of disease at 18 months after right radical orchiectomy. Ki67 may be potentially a good maker for differentiating low-grade from high-grade mesothelioma.

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    • "It is infrequently seen in other anatomic sites, such as the pleura, pericardium, and tunica vaginalis. To our knowledge there have only been 19 well-documented case reports of paratesticular WDPM.1,2,3,4,5,6,7,8,9,10,11 Little is known about the clinicopathologic spectrum of this enigmatic neoplasm or of its overall prognosis. "
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    ABSTRACT: Well-differentiated papillary mesothelioma is an uncommon tumor of the testes that usually presents as a hydrocele. Here, we present the case of one patient who did not have a history of asbestos exposure. The tumor was localized in the tunica vaginalis and was composed of three pedunculated masses macroscopically. Microscopically, branching papillary structures with focal coagulative necrosis were present. In addition to immunohistochemistry, simian virus 40 DNA was also tested by polymerase chain reaction. This report presents one case of this rare entity, its clinical and macroscopic features, and follow-up results.
    The Korean Journal of Pathology 06/2014; 48(3):225-8. DOI:10.4132/KoreanJPathol.2014.48.3.225 · 0.17 Impact Factor
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    ABSTRACT: Well-differentiated papillary mesotheliomas have rarely been reported to involve the testis tunica vaginalis. While the classic histology of the originally described well-differentiated papillary mesotheliomas consisted of papillae lined by a single layer of bland cuboidal cells, more complex architectural patterns have been described. This report details our experience with eight paratesticular mesotheliomas that span the histological spectrum from classic well-differentiated papillary mesotheliomas to those with more complex patterns. We attempt to determine whether there are prognostic or immunohistochemical differences between these lesions and 28 diffuse malignant mesotheliomas. All cases had papillary/tubulopapillary in addition to more complex architectures (cribriform, condensed) and none showed evidence of invasion. Mitotic figures were present in seven cases and averaged 2.1 mitosis per 50 h.p.f. All cases showed <or=1% of positive cells staining for Ki-67 and p53, and only one case stained positive for GLUT-1 in comparison with 50% positivity for GLUT-1 in diffuse mesotheliomas. Of five patients with follow-up information of more than 1 year, three patients were alive at 2, 3 and 9 years, and two died of unknown causes at 5 and 47 years, suggesting that these lesions behave more indolently than typical malignant mesotheliomas of the tunica vaginalis. If these cases were diffuse malignant mesotheliomas, one would have expected at least some of the patients to have died of disease within a couple of years after diagnosis. However, detailed and long-term follow-up were not sufficiently available to reach definitive conclusions on the true biological behavior of these tumors. The morphological continuum noted between our cases and classic well-differentiated papillary mesotheliomas, combined with their immunohistochemical profile and indolent behavior, contrasts with that of diffuse malignant mesotheliomas. We propose that these tunica vaginalis mesotheliomas, which are more complex than the classic well-differentiated papillary mesotheliomas, and yet are not overtly histologically malignant, be classified as 'mesotheliomas of uncertain malignant potential'.
    Modern Pathology 08/2010; 23(8):1165-72. DOI:10.1038/modpathol.2010.113 · 6.19 Impact Factor
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    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. Virtual Slides The virtual slide(s) for this article can be found here:
    Diagnostic Pathology 08/2011; 6(1):78. DOI:10.1186/1746-1596-6-78 · 2.60 Impact Factor
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