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.

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.

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.

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.

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.

Primary mesotheliomas of the tunica vaginalis testis are very rare malignant tumors. They are generally associated with exposure to asbestos. They may manifest as hydrocele, testis tumor, inguinal hernia, or epididymitis. After differential diagnosis, treatment is primarily surgical. Adjuvant therapeutic methods for mesotheliomas of the tunica vaginalis testis, with their high mortality, are controversial. Here, we present a mesothelioma case derived from tunica vaginalis testis acting as long-term pyocele with no known asbestos exposure.

Pleomorphic rhabdomyosarcoma (RMS) of the spermatic cord is a group of rare neoplasms, and a secondary hydrocele testis occasionally occurs. The misdiagnosis of paratesticular mass may lead to a therapeutic delay.

A 79-year-old man presented to our clinic complaining of a 1-mo history of painless scrotal swelling. Physical examination revealed approximately a 15 cm × 10 cm × 5 cm inguinal mass with limited mobility. Contrast-enhanced magnetic resonance imaging showed a hydrocele testis, several enlarged inguinal lymph nodes, and a heterogeneously enhanced lesion with a relatively well-defined margin in the left inguinal region. Due to the imaging findings, he was diagnosed with pleomorphic RMS and received a wide resection of the mass, an inguinal incision with a high section of the left spermatic cord, and a left radical orchiectomy. He experienced local relapse 1 mo postoperatively and received radiotherapy and anlotinib hydrochloride-based immunotherapy as adjuvant therapy. The patient died 3 mo after the surgery.

The optimal interventions for advanced-stage pleomorphic RMS patients should be investigated by more preclinical studies and clinical trials. Physicians need to be aware of the occurrence of pleomorphic RMS in unusual locations, especially when accompanied by a hydrocele testis.

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.

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.

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.

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.

Malignant mesothelioma of the tunica vaginalis testis is an extremely rare tumor without specific clinical manifestations, mainly including hydrocele formation and a painless mass. We herein present the case of a patient with hydrocele of the left testis, without any other complaints. Tunica vaginalis subinvolution was performed, and postoperative pathological examination revealed a malignant mesothelioma arising from the left tunica vaginalis testis. Whole-body positron emission tomography-computed tomography (PET-CT) and subsequent abdominal and pelvic magnetic resonance imaging (MRI) revealed no evidence of local lymphadenopathy. Radical left orchiectomy was performed after the pathological diagnosis. The pathological examination after the second surgery demonstrated that the tumor had invaded the adjacent periorchium and spermatic cord, but there was no evidence of local lymph node metastasis. Pemetrexed and cisplatin were administered at a dose of 900 and 130 mg, respectively, on the first day of a 28-day cycle. After 6 months of therapy, the disease had not progressed on abdominal and pelvic PET-CT and MRI. The patient was still followed up in our urology outpatient clinic at the time of the present report. Although testicular hydrocele is a common and easily diagnosed condition, detailed medical history and physical examination are required. Thus, when clinicians encounter patients with testicular hydrocele, a variety of possible causes must be considered, including testicular or paratesticular tumors, even rare tumors such as mesothelioma of the tunica vaginalis testis.

Malignant mesothelioma most commonly arises in the pleura and peritoneum but also occurs rarely at other anatomical sites with mesothelial tissue, namely, the pericardium and tunica vaginalis testis (TVT). This review provides a better understanding of the epidemiology of mesothelioma of these extrapleural sites.

We conducted a systematic review of the epidemiologic and clinical literature on pericardial mesothelioma and mesothelioma of the TVT. We also analyzed U.S. Surveillance, Epidemiology, and End Results cancer registry data to describe incidence patterns of these malignancies.

An etiologic role of asbestos exposure has been hypothesized for pericardial and TVT mesotheliomas, but no analytical case-control epidemiologic studies exist to test this relationship. A substantial proportion of cases with these malignancies report no known asbestos exposure. In large occupational cohorts with heavy asbestos exposures, no cases of pericardial or TVT mesothelioma have been reported. Trends in the incidence of these malignancies do not match those of pleural mesothelioma, which correspond to historical trends of commercial asbestos use. A male preponderance of pericardial mesothelioma is not evident.

In the absence of analytic epidemiologic studies, the etiologic role of environmental risk factors for mesothelioma of the pericardium and TVT remains elusive.

Primary spermatic cord malignant mesothelioma is an extremely rare tumour with only 12 cases reported so far. It is an aggressive tumour with a high recurrence rate. A 45-year-old man presented with a slow growing right inguinal swelling for the past 1 year. Physical examination revealed a well-circumscribed, hard, non-reducible swelling palpable along the medial extent of the inguinal canal with no cough impulse. Fine-needle aspiration cytology suggested metastatic carcinoma. Contrast-enhanced CT of the thorax and abdomen did not reveal any primary. Right high inguinal orchidectomy was performed at another institution. Postoperative histopathological examination (HPE) and immunohistochemistry suggested biphasic malignant mesothelioma with resected margin positive. The patient was referred to us for revision surgery and adjuvant therapy. Postoperative course was uneventful. Currently, he is undergoing radiotherapy.Surgery is the first-line treatment. Patients should receive adjuvant radiotherapy and/or chemotherapy and long-term follow-up surveillance.

Testicular tumours have many different manifestations, including hydrocele formation. Herein, we present an extremely rare case of testicular mesothelioma presenting with left hydrocele, but without risk factors. Left radical inguinal orchidectomy was performed, and pathological examination revealed a malignant mesothelioma of the tunica vaginalis of the testis. No infiltration of the spermatic cord was evident, and upon advanced radiological evaluation, no sign of metastasis was detected. Follow-up was still ongoing in our urology outpatient clinic at the time of this report. Although hydrocele is a simple and common condition that is easy to diagnose, a detailed investigation should be performed. Thus, when encountering a patient with hydrocele, the clinician should evaluate the possibility of the presence of an underlying testicular/paratesticular tumour, including a rare one such as mesothelioma of the tunica vaginalis.