Well-differentiated papillary mesothelioma occurring in the tunica vaginalis of the testis with contralateral atypical mesothelial hyperplasia

Malignant Para-Testicular Mesothelioma: A Rare Presentation in the Tunica Vaginalis of an Elderly Male With No Prior Asbestos Exposure

Malignant mesothelioma of the tunica vaginalis is an extremely rare and aggressive tumor that is frequently encountered in elderly patients. The diagnosis of malignant mesothelioma of the tunica vaginalis poses a diagnostic challenge due to its infrequency and nonspecific clinical presentation. Histopathological examination and immunohistochemical staining are essential in differentiating this tumor from other para-testicular masses and establishing a definitive diagnosis. Early detection and comprehensive treatment planning are crucial for improving the prognosis and overall outcomes for patients with this rare malignancy. We present a report of malignant mesothelioma of the tunica vaginalis in a 78-year-old male patient with no history of asbestos exposure who presented with a large infiltrative left para-testicular mass. Histopathological examination revealed a biphasic proliferation composed of epithelioid and spindle cells with infiltrative features, foci of necrosis, and increased mitotic figures. Immunohistochemical staining exhibited positive staining for WT1, D2-40, and calretinin, supporting the mesothelial origin of the tumor. Notably, BerEP4 staining was negative, arguing against carcinoma. Immunostaining for keratin 5 was positive, supporting the mesothelial differentiation. The Ki67 proliferation index was high. The differential diagnosis included adenomatoid tumors, germ cell tumors, and pleomorphic sarcoma. We aim to discuss the clinical presentation, diagnostic approach, and therapeutic approaches of this rare entity.

Benign Mesothelial Proliferations of the Tunica Vaginalis Testis

The correct diagnosis of mesothelial proliferations is a classic problem for pathologists, and one which has important clinical implications. A significant number of such cases appear associated with recurrent hydrocele, as an irritative/reactive response to this condition. The morphological spectrum of mesothelial lesions in this topography is broad, and a set of benign conditions may appear, sometimes with florid gross features and cytologic pseudo-atypia. Here, we present two different examples in which malignancy was initially considered in the differential diagnosis.

Well-differentiated Papillary Mesothelial Tumour of the Tunica Vaginalis Testis - A Rare Lesion, but one Pathologists Should Know About Two Patient Reports and a Review of the Literature

Besides malignant mesothelioma, benign mesothelial neoplasms do exist in the tunica vaginalis testis. However, histological criteria remain controversial, thus leading to diagnostic uncertainty and difficulty in their classification according to their biological behavior. In recent years, molecular markers have emerged that aid in the differentiation of benign and malignant mesothelial proliferations throughout the body. Here, we present two middle-aged men with well-differentiated papillary mesothelial tumors and a review of the literature. By now, more than a year after surgery, one patient showed no recurrence of disease after partial or complete orchiectomy without further treatment, for the second no information is available. In conclusion, well-differentiated papillary mesothelial tumors represent rare lesions in the tunica vaginalis testis, but one pathologists should know about to prevent unnecessary treatment and suffering of patients.

Malignant Mesothelioma of Tunica Vaginalis Testis: Update for 2022

Malignant mesothelioma of the testicular tunics is rare. About one third of cases are metastatic and carry a poor prognosis. This paper reviews the epidemiology, clinicopathologic features, treatment, and outcome of this entity.

Tunica Vaginalis Thickening, Hemorrhagic Infiltration and Inflammatory Changes in 8 Children with Primary Hydrocele; Reactive Mesothelial Hyperplasia? A Prospective Clinical Study

The aim of this study is to describe an entity of primary hydrocele accompanied with fibrosis, thickening and hemorrhagic infiltration of parietal layer of tunica vaginalis (PLTV). During a 4-year period (2011-2014), 94 boys (2.5-14 years old) underwent primary hydrocele repair. Hydrocele was right sided in 55 (58.5 %), left sided in 26 (28.7%) and bilateral in 12 patients (13.8%). Eighty three out of 94 patients (88.30%) had communicating hydrocele and the rest eleven patients (11.7%) had non-communicating. Our case group consists of 8 patients (8.51%) based on operative findings consistent with PLTV induration, thickening and hemorrhagic infiltration. Preoperative ultrasonography did not reveal any pathology of the intrascrotal structures besides hydrocele. There weren't hyperechoic reflections or septa within the fluid. Evaluation of thickness of the PLTV was not feasible. Presence of lymph or exudate was excluded after fluid biochemical analysis. Tunica vaginalis histological examination confirmed thickening, hemorrhagic infiltration and inflammation, while there was absence of mesothelial cells. Immunochemistry for desmin was positive, excluding malignant mesothelioma. One patient underwent high ligation of the patent processus vaginalis and PLTV sheath fenestration, but one year later, he faced a recurrence. An elective second surgery was conducted via scrotal incision and Jaboulay operation was performed. The latter methodology was our treatment choice in other 7 out of 8 patients. During a 2-year postoperative follow-up, no other patient had any recurrence. We conclude that in primary hydrocele with macroscopic features indicative of tunica vaginalis inflammation, reversion of the tunica should be a part of operative strategy instead of sheath fenestration, in order to minimize the recurrence.

Well-differentiated papillary mesothelioma of tunica vaginalis testis of unknown malignant potential: Sonographic appearance

Paratesticular mesothelioma is a rare differential diagnosis in the presence of scrotal hydrocele. A 17-year-old boy presented with a 3-year history of progressive hydrocele. Sonography revealed a large left paratesticular mass within the hydrocele. Serum tumor markers were negative. Left hydrocelectomy was performed and pathological analysis of the epididymal mass revealed a well-differentiated papillary mesothelioma. We discuss the sonographic and pathological findings of this rare neoplasm.

Images - Well-differentiated papillary mesothelioma of the tunica vaginalis

Well-differentiated papillary mesothelioma (WDPM) is a rare mesothelial tumour occurring in the tunica vaginalis of the testicle. The pathological classification of paratesticular mesothelial tumours is controversial and continues to evolve in the literature. Diagnostic criteria of one subtype, WDPM, are histological and include the following: 1) papillary or tubular-papillary architecture; 2) bland nuclear cytology; 3) low mitotic activity; 4) lined by a single row of cuboidal cells; and 5) absence of stromal invasion.1,2 This report presents issues of diagnosis of this rare pathology with imaging from an example case.

Two Case Reports of Benign Testicular Mesothelioma and Review of the Literature

Mesothelioma is usually diagnosed in people over the age of 50 with large history of asbestos-related exposure. It is frequently located in pleural cavity, peritoneum, and pericardium. At the testicles the mesothelioma had been reported first in 1957 like a malignant non-germ-cells tumor. The objective is to present two case reports of benign testicular mesothelioma and review of the literature.

A Case of Solitary Well-Differentiated Papillary Mesothelioma with Invasive Foci in the Pleura

Well-differentiated papillary mesothelioma (WDPM) is a rare, distinct tumor consisting of mesothelial cells with a papillary architecture, bland cytological features, and a tendency toward superficial spread without invasion. Rare cases with superficial invasion are termed WDPM with invasive foci. We report a case of solitary WDPM with invasive foci in the pleura. A 61-year-old woman presented with a lung adenocarcinoma. A small papillary lesion measuring 29 × 10 × 8 mm was incidentally found in the parietal pleura during a lobectomy for the lung adenocarcinoma. The fibrovascular core of the small papillary lesion was surrounded by a single layer of cuboidal cells with mild to moderate atypia and large nucleoli. Atypical mesothelial cells focally invaded the submesothelial layer. The cells of the papillary lesion were positive for cytokeratins and mesothelial markers. The Ki67 index was <1 %. The lesion did not show p16 loss on fluorescence in situ hybridization. We could not detect atypical mesothelial cells in the specimen from an extrapleural pneumonectomy. WDPM with invasive foci is prone to multifocality; however, our case represents a solitary case in the pleura.

Case Report of a Well-Differentiated Papillary Mesothelioma of the Tunica Vaginalis in an Undescended Testis With Review of Literature

Well-differentiated papillary mesothelioma (WDPM) affecting the tunica vaginalis testis is a rare tumor, and very little is known about the clinicopathological spectrum of this variant as a distinct entity. Most patients with WDPM suffer from scrotal pain or swelling, but hydrocele seems to be the most common presenting symptom. These lesions are usually not aggressive and are accompanied by an indolent clinical behavior. In this article, we report the first case known of WDPM in an undescended testis, and in addition, we review the literature for similar cases.

Well-differentiated papillary mesothelioma of the tunica vaginalis: a case study and review of the literature

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.

Benign cystic mesothelioma: a rare cause for scrotal swelling

Benign cystic mesothelioma of the tunica vaginalis is a rare occurrence. It usually presents with painless gradual swelling in the scrotum. These types of benign mesotheliomas typically occur in the peritoneum and usually affect young to middle-aged patients. We present in this case an unusual case of benign cystic mesothelioma of the tunica vaginalis in a 77-year-old male patient.

Rare Tumors of the Testis and Mesothelial Proliferation in the Tunica Vaginalis

An increasing number of rare testicular tumors have been recognized in the recent years with a wide and heterogeneous spectrum of morphologies. The utility of ancillary studies, including immunohistochemistry, is often limited and is important for the pathologists to be aware of these entities, because they require a comprehensive pathological and clinical approach for an appropriate treatment.

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

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.

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

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.

Mesothelioma of the tunica vaginalis: a series of eight cases with uncertain malignant potential

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'.

US of the tunica vaginalis testis: anatomic relationships and pathologic conditions

Extratesticular lesions are common incidental findings at ultrasonography (US) among men and boys. Most lesions originate from or depend on the tunica vaginalis, a mesothelium-lined sac with a visceral layer and a parietal layer. The tunica vaginalis is formed when the superior portion of the processus vaginalis closes during embryologic development. Abnormal closure of the processus vaginalis leads to congenital anomalies of the tunica vaginalis, such as complete or partial patency of the processus vaginalis, spermatic cord hydrocele, and inguinoscrotal hernia. The proximity of the visceral layer to the testis explains the reactive involvement seen in epididymo-orchitis, with resultant pyocele or abscess formation. The tunica vaginalis also may be affected by inflammatory and traumatic disorders such as scrotal calculi, fibrous pseudotumor, or hematocele. These lesions manifest as solid or heterogeneous tumorlike masses. Lesions of mesothelial origin, such as adenomatoid tumor, tunica cyst, and mesothelioma, may involve the tunica vaginalis. Entrapped mesenchymal cells can lead to lipoma, leiomyoma, or sarcoma, although these tumors are uncommon in the tunica vaginalis. US is not useful for differentiating between benign and malignant tumors; however, some characteristic findings may help in planning the best surgical approach. Knowledge of the embryologic development, anatomic relationships, and pathologic disorders of the tunica vaginalis is essential to narrow the differential diagnosis of an extratesticular lesion. In most cases, US findings in combination with clinical assessment can indicate whether nonsurgical management or testis-sparing surgery is warranted.

Paratesticular mesothelioma. Report of a case with comprehensive review of literature

Paratesticular mesotheliomas are rare tumors with 223 cases described so far. The sole plausible causative factor so far ascertained in the pathogenesis of these tumors is asbestos, which however is found in only around 30% to 40% of such cases. The age range of affected individuals is wide, mostly adults and the elderly, but also includes young people and children. The most common presenting symptom is either hydrocele of unknown origin or intrascrotal mass. When hydrocele is the presenting symptom, these tumors are often clinically overlooked and the diagnosis is delayed. Most paratesticular mesotheliomas arise in the tunica vaginalis, but primary tumors of the spermatic cord and epididymis are also on record. Tumors arising from the peritoneal mesothelium of a hernia sac are excluded from this group. The correct diagnosis is almost always made after histologic examination of the operative specimen. Immunohistochemistry and electron microscopy are always helpful and sometimes necessary tools for diagnosis. So far very few cases have been identified or suspected preoperatively on cytologic examination. Three clinicopathologic types of malignant mesotheliomas of the male genital tract are recognized: diffuse tubulo-papillary mesothelioma, well-differentiated papillary mesothelioma, and multicystic mesothelioma. The histologic subtypes are almost always pure epithelial or biphasic. The differential diagnosis is mainly with serous papillary tumors arising from Mullerian vestiges, but several diverse primary or secondary tumors also need to be considered. A clinicopathologic evaluation of a case of tunical diffuse mesothelioma in a 74-year-old male from the AMR Series is the starting point for this general review.

Pseudoneoplastic lesions of the testis and paratesticular structures

Pseudotumors or tumor-like proliferations (non-neoplastic masses) and benign mimickers (non-neoplastic cellular proliferations) are rare in the testis and paratesticular structures. Clinically, these lesions (cysts, ectopic tissues, and vascular, inflammatory, or hyperplastic lesions) are of great interest for the reason that, because of the topography, they may be relevant as differential diagnoses. The purpose of this paper is to present an overview of the pseudoneoplasic entities arising in the testis and paratesticular structures; emphasis is placed on how the practicing pathologist may distinguish benign mimickers and pseudotumors from true neoplasia. These lesions can be classified as macroscopic or microscopic mimickers of neoplasia.

Multicystic and well-differentiated papillary peritoneal mesothelioma treated by surgical cytoreduction and hyperthermic intra-peritoneal chemotherapy (HIPEC)

BACKGROUND

Multicystic peritoneal mesothelioma (MPM) and well-differentiated papillary peritoneal mesothelioma (WDPPM) are exceedingly uncommon lesions with uncertain malignant potential and no uniform treatment strategy. The aim of the current study was to review our experience with cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) in these clinical settings.

METHODS

Four women with MPM and eight with WDPPM underwent 13 procedures of cytoreduction and close-abdomen HIPEC with cis-platin and doxorubicin. Seven patients had recurrent disease after previous debulking (one operation in five patients, two in one, four in one). Potential clinicopathological prognostic factors were assessed.

RESULTS

Optimal cytoreduction (residual tumor nodules <or=2.5 mm) was performed in 12 of 13 procedures. Median follow-up was 27 months (range 6-94). One grade 4 postoperative complication (NCI/CTCAE v.3.0) and no operative mortalities occurred. One patient underwent the procedure twice due to locoregional MPM recurrence. Transition of typical WDPPM to malignant biphasic mesothelioma was documented in one patient who died of disease progression following incomplete cytoreduction and HIPEC. Following multimodality treatment, 5-year overall and progression-free survival were 90.0% (standard error = 9.0) and 79.7% (11.9), respectively. Progression-free survival following previous debulking surgery (median 24 months; range 2-87) was statistically worse (P = .0156). Incomplete cytoreduction and poor performance status correlated to both reduced overall and progression-free survival after cytoreduction and HIPEC.

CONCLUSIONS

MPM and WDPPM are borderline tumors capable of transformation into potentially lethal processes. Definitive tumor eradication by means of cytoreduction and HIPEC seems more effective than debulking surgery in preventing disease recurrence or transition to aggressive malignancies.