Malignant mesothelioma of the tunica vaginalis testis: a case report and review of the literature

Mesothelioma of the Tunica Vaginalis Testis: Diagnostic and Therapeutic Management. A Comprehensive Review, 1982-2024

BACKGROUND

Mesothelioma of the tunica vaginalis testis (MTVT) is an extremely rare and aggressive cancer. The diagnosis and management of MTVT is complex, and no standard treatment protocol is available.

METHODS

We conducted a systematic literature review from 1 January 1982 to 14 March 2024 using PubMed to collect all the available case reports and case series. A descriptive analysis of patient characteristics with clinical presentation, diagnostic work-up, therapeutic management, and past asbestos exposure was performed. Survival times of patients treated with different therapeutic approaches were evaluated.

RESULTS

Overall, 289 patients with MTVT were included in our analysis. The most common clinical presentations were scrotal/testicular swelling or mass (187 patients, 65%) and the presence of hydrocele (159, 55%). Imaging evaluation, mostly with ultrasonography or CT scan, was reported in two-thirds of cases. Radical surgery (216 patients, 75%) with orchiectomy and, in select cases, hemiscrotectomy and inguinal lymphadenectomy was the most frequent therapeutic approach. A minority of patients (49, 17%) received adjuvant therapy after surgery (radiotherapy, chemotherapy, or a combination of the two), with no evidence of survival improvement.

CONCLUSIONS

No standard guidelines for MTVT are available so far. Radical surgery following accurate radiological staging should be the mainstay of treatment. The role of adjuvant treatments remains undefined. Due to its rarity, MTVT should be treated in referral centers, and patients' data should be collected in a dedicated register in order to improve the knowledge of this exceedingly rare disease and establish optimal diagnostic and therapeutic management.

A rare malignant mesothelioma of the tunica vaginalis testis: A case report

Malignant mesothelioma of the tunica vaginalis testis is a rare, highly invasive urogenital malignant tumor with no specific clinical manifestations. Reported cases of this disease are limited. Therefore, an early preoperative diagnosis is difficult. The current study presents a case of malignant mesothelioma of the tunica vaginalis testis and a literature review. A 52-year-old man was admitted to Xiaoshan Affiliated Hospital of Wenzhou Medical University (Hangzhou, China) in December 2022 and underwent radical resection of the right testicle and epididymis but did not undergo radiotherapy or chemotherapy. The patient was followed up for 5 months, and no recurrence or metastasis was found. The rarity of testicular mesothelioma poses a challenge to its etiology and diagnosis, which is rarely achieved preoperatively. Malignant mesothelioma of the testicular tunica vaginalis has a poor prognosis and is not sensitive to radiotherapy or chemotherapy, requiring close postoperative follow-up. This condition is rare in clinical practice; therefore, it needs to be reported to aid clinicians' decision-making regarding diagnosis and treatment.

Well-Differentiated Papillary Mesothelial Tumor of the Scrotum with Suspicious Invasion

Well-differentiated papillary mesothelial tumor (WDPMT) is a distinct form of mesothelioma with low malignant potential and is mostly found in the peritoneal cavity. It consists of mesothelial cells with papillary structure and bland cytology. We report a rare case of WDPMT with suspicious invasive foci in the tunica vaginalis. WDPMT with invasive foci is known to have a tendency for recurrence. Therefore, careful attention should be given to properly diagnosing and treating this rare entity.

Association between asbestos exposure and pericardial and tunica vaginalis testis malignant mesothelioma: a case-control study and epidemiological remarks

Objectives The purposes of this study are to describe the epidemiology of pericardial and tunica vaginalis testis mesothelioma and assess the role of asbestos exposure for these rare diseases. Methods Based on incident pericardial and tunica vaginalis testis mesothelioma cases collected from the Italian national mesothelioma registry (ReNaM) in the period 1993-2015, incidence rates, survival median period and prognostic factors have been evaluated. A case-control study has been performed to analyze the association with asbestos exposure (occupational and non-occupational) for these diseases. Results Between 1993 and 2015, 58 pericardial (20 women and 38 men) and 80 tunica vaginalis testis mesothelioma cases have been registered with a mean annual standardized (world standard population as reference) incidence rates of 0.049 (per million) in men and 0.023 in women for the pericardial site, and 0.095 for tunica vaginalis testis mesothelioma. Occupational exposure to asbestos was significantly associated with the risk of the diseases [odds ratio (OR) 3.68, 95% confidence interval (CI) 1.85-7.31 and OR 3.42, 95% CI 1.93-6.04 in pericardial and tunica vaginalis testis mesothelioma, respectively]. The median survival was 2.5 months for pericardial and 33.0 months for tunica vaginalis testis mesotheliomas. Age was the main predictive factor for survival for both anatomical sites. Conclusions For the first time in an analytical study, asbestos exposure was associated with pericardial and tunica vaginalis testis mesothelioma risk, supporting the causal role of asbestos for all anatomical sites. The extreme rarity of the diseases, the poor survival and the prognostic role of age have been confirmed based on population and nationwide mesothelioma registry data.

Asbestos exposure and malignant mesothelioma of the tunica vaginalis testis: a systematic review and the experience of the Apulia (southern Italy) mesothelioma register

BACKGROUND

Malignant mesothelioma of the tunica vaginalis testis (MMTVT) is a rare disease with a poor prognosis. The diagnosis and management of these lesions are often difficult for pathologists, surgeons, oncologists and occupational physicians. A preoperative diagnosis of malignancy is rarely made, and there is no established effective therapy except orchidectomy.

METHODS

A systematic literature review was conducted among the articles published in the English literature on primary MMTVT. Moreover four cases from the Apulia mesothelioma register are reported here.

RESULTS

Two hundred eighty-nine cases of MMTVT have been reported from 1943 to 2018. Overall asbestos exposure has been investigated only for 58% of all cases reported in this review, while in 41.8% this data are not available. Noteworthy is the fact that in many reports there is not an anamnestic reconstruction of any asbestos exposure. A history of direct occupational, environmental or familial asbestos exposure is found in 27.6% of the cases. The four cases from the Apulia mesothelioma register are all with ascertained occupational exposure to asbestos.

CONCLUSIONS

The true incidence of asbestos exposure in MMTVT is underestimated because of insufficient information reported in older literature. To establish a broad consensus on the causal relationship between asbestos and MMTVT in the scientific community its necessary to analyze the same variables in the epidemiological studies. In general it should be recommended that a positive history of exposure to asbestos or to asbestos-containing materials are at risk for the development of a MMTVT and should be monitored.

The legacy of the F344 rat as a cancer bioassay model (a retrospective summary of three common F344 rat neoplasms)

The Fischer 344 (F344) rat was used by the National Toxicology Program (NTP) for over 5 decades for toxicity and carcinogenicity studies. However, in 2006, the NTP decided to switch to a different rat stock due largely to high background control incidences of Leydig cell tumors (LCTs) and mononuclear cell leukemia (MNCL), also known as large granular lymphocytic (LGL) leukemia. In the current review, we aim (1) to provide a summary of NTP bioassays with treatment-associated effects involving MNCL and LCTs in addition to male F344-specific tunica vaginalis mesothelioma (TVM); (2) to describe important pathobiological differences between these F344 rat tumor responses and similar target tissue-tumor response in humans; and (3) to present the NTP reasons for switching away from the F344 rat. We show that due to the highly variable background incidence of F344 MNCL, more reliance on historical control data than is usual for most tumor responses is warranted to evaluate potential effect of any chemical treatment in this rat strain. The high spontaneous incidence of LCTs in the testes of male F344 rats has made this tumor endpoint of little practical use in identifying potential testicular carcinogenic responses. TVM responses in F344 rats have a biological plausible relationship to LCTs unlike TVM in humans. Given their high spontaneous background incidence and species-specific biology, we contend that MNCL and LCT, along with TVM responses, in F344 rat carcinogenicity studies are inappropriate tumor types for human health risk assessment and lack relevance in predicting human carcinogenicity.

Malignant mesothelioma of the tunica vaginalis testis: diagnostic studies and differential diagnosis

Malignant mesothelioma of the tunica vaginalis testis is an extremely rare tumor representing 0.3% to 5% of all malignant mesotheliomas. Gross examination of testicular mesotheliomas typically reveals tumor nodules studding the thickened tunica vaginalis and, in some cases, infiltrating the testicular parenchyma, leading to diagnostic challenges. Microscopically, the tumor is characterized by epithelioid cells arising from the tunica vaginalis with papillary, tubulopapillary, or solid architectural patterns. The papillae are usually lined by a single layer of cells with relatively bland cytologic features. An epithelial cell phenotype admixed with a sarcomatoid pattern has also been described in a few cases. Immunohistochemically, the tumor is usually positive for calretinin, Wilms tumor-1, epithelial membrane antigen, D2-40, thrombomodulin, cytokeratin 7, and cytokeratin 5/6. Electron microscopic studies reveal epithelial cells joined by tight junctions, forming lumina, and displaying long microvilli with length to width ratios often greater than 10. The most important differential diagnostic considerations include florid mesothelial hyperplasia, adenomatoid tumor, carcinoma of the rete testis, and serous papillary tumors. In addition, the various types of testicular germ cell tumors should be considered, including seminomas, embryonal carcinomas, and intratubular germ cell tumors, particularly in tumors with testicular parenchymal involvement. Pleomorphic sarcomas should also be considered, particularly when dealing with the biphasic variant. The prognosis for this entity is grave, with a median survival of 23 months. Aggressive therapy with radical orchiectomy remains the mainstay of treatment.

[Pleuro-pulmonary metastases from a malignant mesothelioma of the tunica vaginalis]

INTRODUCTION

Mesothelioma is a malignant tumour of the serous membranes that principally affects the pleura. Peritoneal, pericardial and tunica vaginalis mesothelioma are very rare.

CASE REPORT

We report the case of a 65-year-old male with malignant mesothelioma of the tunica vaginalis (MTV). He presented with several local recurrences and, five years after the initial surgery, with pulmonary nodules and a pleural effusion. Pleural biopsies confirmed epithelioid mesothelioma. A diagnosis of pleuro-pulmonary metastases from previous malignant MTV was made.

CONCLUSIONS

Malignant MTV is a rare and aggressive tumor with frequent local recurrences and, rarely, visceral metastases. This case report emphasizes the difficulties of the differential diagnosis between pleural mesothelioma and pleural metastases from MTV. The lack of any treatment for metastatic malignant MTV is discussed.

Malignant Mesothelioma of the Tunica Vaginalis Testis in a Dog: Histological and Immunohistochemical Characterization

Histologic and immunohistochemical features of a malignant mesothelioma of the testicular tunica vaginalis in a 9-year-old male mixed-breed dog are reported. The dog had a large scrotal swelling determined by ultrasonography to be a heterogeneous irregular mass characterized by a mixed echogenic pattern and located in the left vaginal canal of the testis. Histologically, the neoplasm was nodular, was poorly demarcated, and consisted of pleomorphic cells that were associated with a significant desmoplastic reaction. By immunohistochemistry, neoplastic cells stained positively for cytokeratin and vimentin and were immunoreactive with an antimesothelial cell monoclonal antibody. Malignant mesotheliomas of tunica vaginalis testis are rare in mammalian species, including dogs.

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.

Immunohistochemical Profile of Paratesticular Serous Papillary Adenocarcinoma and Tunica Vaginalis Facilitates Distinction From Malignant Mesothelioma

Testicular and paratesticular tumors resembling mullerian epithelium of the ovary are extremely uncommon. This study reports a case of paratesticular serous papillary adenocarcinoma (SPA) in an 87-year-old man that was misdiagnosed as malignant mesothelioma (MM) and is 37 years older than previous cases, highlighting that SPA does not occur exclusively in young patients as described. Immunohistochemistry revealed expression of pankeratin, CAM 5.2, CK7, CK903, Ber-EP4, vimentin, S100, and CEA and virtually no expression of CK5/6, CK20, calretinin, thrombomodulin, or glypican 3. Expression of adjacent nonneoplastic tunica vaginalis mesothelium was assessed in this patient and additional specimens. Profiles of paratesticular SPA and MM were summarized and compared with paratesticular mesothelium. Nontumoral stromal and entrapped mesothelial expression were 2 diagnostic pitfalls in this case that have not been previously described. Based on these data, a panel of markers and the use of sections containing nonneoplastic mesothelium to facilitate interpretation is recommended.

Adrenal failure caused by a retroperitoneal malignant mesothelioma

A 62-year-old man presented with clinical signs of acute abdominal pain and adrenal insufficiency. Computerized tomographic scans revealed bilateral adrenal tumors and the left adrenal tumor was surgically resected. The patient was found to have retroperitoneal mesothelioma presenting as bilateral metastatic adrenal tumors, which were well controlled by systemic chemotherapy with CDDP and 5-FU. This case appears to be the first reported case in the literature of adrenal failure due to bilateral adrenal infiltration caused by retroperitoneal malignant mesothelioma.