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

Timely Surgical Resection Achieved Prolonged Remission in Patients With Malignant Mesothelioma of the Tunica Vaginalis Testis and Retroperitoneal Recurrence

Malignant mesothelioma of the tunica vaginalis testis (MMTVT) is a rare tumor of the testicular sheath. More than 50% of cases initially present as recurrent hydrocele, but there have also been documented cases with hematocele, inguinal hernia, or epididymitis. Due to the non-specific symptoms and signs of the disease, it is almost always diagnosed intra- or postoperatively. The lack of standardized therapy protocols, as well as the lack of evidence supporting systemic chemotherapy, have fueled arguments in favor of the necessity of retroperitoneal lymph node dissection (RPLND) in the treatment of the disease, especially in the case of lymph node metastasis. We present a case of MMTVT achieving prolonged remission after timely and extensive surgical treatment.

Testicular/paratesticular mesothelial tumours: Uncommon histopathologic entities in a very complex anatomical site

Mesothelial tumours of the testicular/paratesticular region are uncommon, poorly characterised and difficult-to-diagnose lesions. They encompass entirely benign proliferations (adenomatoid tumour) and malignant, very aggressive tumours (mesothelioma) whose morphological features can be overlapping, highly variable and confounding. Moreover, testicular/paratesticular mesothelial tumours comprise relatively new entities with indolent behaviour (well-differentiated papillary mesothelial tumour) as well as tumours which cannot be correctly included in any of the aforementioned categories and whose classification is still controversial. The molecular profile of such tumours represents an open issue. In fact, despite the recent discoveries about the genomic landscape of mesothelial proliferations at other sites (pleura, peritoneum), testicular/paratesticular mesothelial tumours, and namely mesotheliomas, are too rare to be extensively studied on large case series and they could arguably hide relevant differences in their molecular background when compared to the more common pleural/peritoneal counterparts.The aim of this review is to provide a guide for the pathological assessment of testicular/paratesticular mesothelial tumours. Herein, we describe the most recent updates on this topic according to the latest (year 2022) World Health Organisation Classification of Urinary and Male Genital Tumours (5th edition) and current literature. The diagnostic criteria, the main differentials and the role of ancillary techniques in the diagnosis of mesothelial testicular/paratesticular tumours are discussed.

Multimodal Management of Testicular Mesothelioma - A Retrospective Analysis From a Tertiary Cancer Care Centre

The main modality of management of paratesticular mesothelioma remains orchiectomy while the use of adjuvant chemotherapy has not yet been explored. We aim to analyse the outcome of the multimodal management protocol in testicular mesothelioma We conducted a retrospective analysis of patients registered and treated for testicular mesothelioma between 2009 and 2019 in an oncology tertiary care hospital. Patients presenting with nodal, metastatic disease were treated with adjuvant, palliative chemotherapy respectively and their response to treatment was periodically monitored. Eight patients (3 early, 1 nodal, 4 metastatic) with median age of 58 years was included in the study. Patients who had limited (early, nodal) disease (n = 4) had overall survival ranging from 20 to 140 months while metastatic disease (n = 4) had poor outcomes with overall survival ranging from 2 to 13 months. Surgery remains to be an important modality of therapy that improves the local control and overall outcomes and the quality of life even in patients with metastatic disease at the time of diagnosis. Adjuvant chemotherapy might play a role in effective management of locoregional disease. The performance status, the extent of disease at the time of presentation are the important prognostic factors in deciding the outcome of the disease management.

A population-based evaluation of tunica vaginalis mesothelioma: An analysis of the National Cancer Database

PURPOSE

Primary mesothelioma of the tunica vaginalis (TVM) is a rare and poorly understood malignancy with insufficient population-level data to guide management decisions.

MATERIALS AND METHODS

A retrospective analysis of TVM cases recorded in the National Cancer Database from 2004 to 2015 was performed. Cases were identified using International Classification of Diseases for Oncology histology codes. Associations between demographic, clinical and therapeutic factors were analyzed using Kaplan-Meier survival estimates for overall survival (OS) and Cox proportional hazard modeling. Propensity score matching for receipt of systemic chemotherapy was performed to assess the impact on OS.

RESULTS

One hundred fifty-one men with a median age of 65 years (interquartile range [IQR] 51-78) were included. Median OS from diagnosis was 72.5 months (IQR 20.2-Not Reached [NR]) after a median follow up of 34.9 months. Multivariate analysis demonstrated an increased risk of death for patients in the fourth quartile of age (hazard ratio [HR] 5.57, 95% confidence interval [CI] 1.70-18.17, P = 0.004), those with biphasic or fibrous histology (HR 2.59, 95% CI 1.15-6.42, P = 0.04) and positive surgical margins (HR 3.27, 95% CI 1.61-6.63, P = 0.001). There was no significant difference in OS associated with receiving chemotherapy (P = 0.5) even after propensity score matching (P = 0.07).

CONCLUSIONS

Margin-negative surgical resection is paramount to improving OS. There are insufficient data to recommend for or against adjuvant systemic chemotherapy or RT, although the limited available data does not suggest apparent benefit in terms of OS.

A case of simultaneous diagnosis of tunica vaginalis testis and pleural mesothelioma

A 37‐year‐old man was admitted to our hospital with chest pain and fever. Computed tomography showed pleural effusion and irregularly marginated, elevated lesions inside diffuse pleural thickening. Detailed medical examination showed swelling of the left testicle. 18F‐fluorodeoxyglucose positron emission tomography showed uptakes at the thickened pleura and left testis. Pelvic magnetic resonance imaging showed a mass in the left testis with a heterogeneous and partially calcified tumour present interiorly. Thoracoscopy was performed under local anaesthesia, enabling the observation of masses at the pleura and biopsy of the mass, which was diagnosed as malignant pleural mesothelioma. The affected testicle was resected and diagnosed as tunica vaginalis testis mesothelioma. Thus, simultaneous tunica vaginalis testis and pleural mesothelioma were diagnosed. It is necessary to closely examine parts of the body other than the chest.

Clinicopathological characteristics and outcomes in men with mesothelioma of the tunica vaginalis testis: analysis of published case-series data

Purpose

Mesothelioma of the tunica vaginalis testis (MTVT) is a rare tumor, and currently, there are no published treatment recommendations.

Methods

We performed a systematic literature review and synthesized clinical presentation, clinicopathological factors associated with metastatic disease, treatment options, and outcomes in men with MTVT.

Results

We included 170 publications providing data on 275 patients. Metastatic disease occurred in 84/275 (31%) men with malignant MTVT: Most common sites included retroperitoneal lymph nodes (LNs) (40/84, 48%), lungs (30/84, 36%), and inguinal LNs (23/84, 27%).

Invasion of the spermatic cord or scrotum was the only risk factor for local recurrence [odds ratio (OR) 3.21, 95% confidence interval (CI) 1.36–7.57]. Metastatic disease was associated with age ≥ 42 years (OR 3.02, 95% CI 1.33–6.86), tumor size ≥ 49 mm (OR 6.17, 95% CI 1.84–20.74), presence of necrosis (OR 8.31, 95% CI 1.58–43.62), high mitotic index (OR 13.36, 95% CI 1.53–116.51) or angiolymphatic invasion (OR 3.75, 95% CI 1.02–13.80), and local recurrence (OR 4.35, 95% CI 2.00–9.44). Complete remission in the metastatic setting was observed in five patients, most of whom were treated with multimodal therapy. Median survival in patients with metastatic disease was 18 months (IQR 7–43).

Conclusion

Malignant MTVT is a rare but aggressive disease. Since local recurrence is a risk factor for metastatic progression, we recommend aggressive local treatment. Survival and response to any treatment in the metastatic setting are limited.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03533-6.

Malignant Mesothelioma of the Tunica Vaginalis Testis-A Malignancy Associated With Asbestos Exposure and Trauma: A Case Report and Literature Review

In this article, we report an unusual case of a malignant mesothelioma of the testis, presenting as hydrocele. The patient has a known medical history of trauma and occupational exposure to asbestos. The clinical features of this injury are discussed together with its immunohistochemistry. Surgical intervention is discussed due to the nature of this pathology.

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

Background

Malignant mesothelioma of the tunica vaginalis is a rare tumour which comprises less than 1% of all mesotheliomas.

Case presentation

69-years old patient with painful hard mass and hydrocele in the right scrotum to whom a right hydrocelectomy was performed. Any history of scrotal trauma or exposure to asbestos was not present. Excisional biopsy revealed a multinodular tumour with focal areas of necrosis and infiltrative growth. According to morphological and immunohistochemical findings, diagnosis of malignant biphasic mesothelioma of the tunica vaginalis testis was made. Two months after hydrocelectomy, right inguinal orchidectomy was performed. Post-surgical whole body CT scan revealed paraaortic and pararenal lymphadenopathy, likely to be metastatic. Adjuvant treatment with 6 cycles of cisplatin and pemetrexed was applied. After 3 cycles of chemotherapy, CT scan showed progression and the treatment was changed to gemcitabine 1 month after.

Conclusions

Although malignant mesothelioma of the tunica vaginalis is a rare malignancy, it poses a diagnostic challenge which can mimic common inguinal or scrotal diseases such as hydrocele. Despite aggressive surgical procedures or adjuvant therapies, the prognosis remains poor.

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.

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.

Malignant Mesothelioma of Tunica Vaginalis Testis: Macroscopic and Microscopic Features of a Very Rare Malignancy

Malignant mesothelioma of the tunica vaginalis testis (MMTVT) is an extremely rare tumour, usually mimicking benign pathologies of the scrotum.

Our case is an 84-year-old male patient who appealed with a painless, left-sided scrotal swelling longer than 2 months. Although the level of tumour markers was normal, ultrasonographic examination results forced us to perform an inguinal scrotal exploration. Multiple small papillary tumours, both on tunica vaginalis and tunica albuginea, were detected intraoperatively. Due to these findings, radical orchiectomy was performed.

A pathological evaluation showed malignant mesothelioma (MM) of the tunica vaginalis testis. Exposure to asbestos is a well-known risk factor. Furthermore, a history of trauma, herniorrhaphy and chronic hydroceles is blamed as a possible risk factor. Scrotal ultrasonography is the mainstay of primary diagnosis and, therefore, it should not be overlooked when dealing with benign scrotal cysts or hydroceles, which are very common pathologies at these decades, too.

Radical inguinal orchiectomy is the primary treatment choice for localised MMTVT disease, whereas in signs of lymph node metastasis, inguinal lymph node dissection is required. Radical resection should be completed with chemotherapy and/or radiotherapy for an advanced or recurrent disease. This case, which is very rarely reported in the literature and detected during inguinal exploration, along with the pathological works that supported the diagnosis, was presented with this report.

Epidemiology of mesothelioma of the pericardium and tunica vaginalis testis

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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

Hydrocele with a surprise: Malignant mesothelioma of the tunica vaginalis - Case report and review of literature

Hydrocele is a very common condition that is simple to evaluate and treat. Management of hydrocele is usually delegated to the junior members of the surgical team. Sometimes this simple condition can spring huge surprises. A 20-year-old man presented with acute onset large, painless fluctuant left hemi-scrotal swelling. Scrotal ultrasonography showed thickened tunica vaginalis. A diagnosis of left hydrocele was made and repair by excision of sac was planned. During the procedure, the sac was found studded with red nodular growths; histopathology reported malignant mesothelioma of tunica vaginalis. Metastatic evaluation showed extensive retroperitoneal lymph nodal involvement. Despite receiving adjuvant chemotherapy with radiotherapy patient died due to extensive metastasis within 16 months. This case is presented for rarity of diagnosis, young age of presentation, absence of etiological factor and rapidly progressive clinical course.

Geographic distribution of incidence of pericardial and paratesticular mesotheliomas in the USA

PURPOSE

Exposure to asbestos is thought to cause the large majority of pleural mesotheliomas in the USA. It is unknown whether asbestos exposure plays a role in the etiology of rarer forms of mesothelioma, e.g., those located in the pericardium or in the tunica vaginalis of the testis. In order to address this question, we sought to determine whether geographic patterns of incidence of these mesotheliomas have paralleled those of pleural mesotheliomas.

METHODS

We used age-adjusted incidence data from the nine populations served by the National Cancer Institute's Surveillance, Epidemiology, and End Results program during 1973-2011. Among men ages ≥50 years, we compared the incidence of pericardial and paratesticular mesotheliomas, respectively, with the incidence of pleural mesothelioma across the nine populations.

RESULTS

The rate of pleural mesothelioma was approximately twice as high in the San Francisco-Oakland (SFO) and Seattle-Puget Sound (SPS) areas compared to the other regions. In contrast, rates of paratesticular and pericardial mesotheliomas were not elevated in SFO (n = 3 paratesticular, 1 pericardial) or SPS (n = 4 paratesticular, 1 pericardial) relative to other regions.

CONCLUSIONS

The results of this ecologic study do not support a role for asbestos exposure in the etiologies of either pericardial or paratesticular mesotheliomas; however, this study was limited by small numbers and was unable to directly ascertain asbestos exposure.

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.

Primary malignant mesothelioma of the spermatic cord

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.

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.

Preoperative cytological diagnosis of malignant mesothelioma of tunica vaginalis

Malignant mesothelioma of tunica vaginalis testis is a rare aggressive neoplasm with ∼200 cases reported so far. A correct preoperative diagnosis of this rare tumor is difficult. Fine-needle aspiration cytology (FNAC) is a rapid and inexpensive diagnostic tool that may prove helpful in such cases. Very few cases have been diagnosed on cytology so far, and the descriptions of the cytological features have rarely been described in the literature. In this report we present the cytological features of malignant mesothelioma of tunica vaginalis testis which was diagnosed by FNAC and subsequently confirmed by histopatholoy and immunohistochemical (IHC) studies.

Malignant Mesothelioma of the Epididymis: A Case Report

Malignant mesothelioma of the epididymis is a very rare tumor. We report a case of a 33-year old male with a left hydrocele that presented for evaluation of infertility. Scrotal ultrasound revealed a left extratesticular mass. Final pathology revealed malignant mesothelioma involving the epididymis, with well differentiated epithelioid morphology. Metastatic workup was negative.

Malignant paratesticular mesothelioma

Mesothelioma of the tunica vaginalis testis (MTVT) is a rare tumor that usually affects patients after the sixth decade of life. Exposure to asbestos is a known risk factor. Enlargement of the scrotal volume is the most common initial clinical manifestation, and about 15% of cases present metastasis at diagnosis. The treatment relies on surgical resection while the role of adjuvant chemotherapy and radiotherapy remains unclear. The prognosis for patients is generally poor, with a lethal outcome in 30% over a 24-month period. The authors report a case of a 62-year-old patient with the diagnosis of MTVT without a history of asbestos exposure. After surgical treatment, metastatic disease ensued. Chemotherapy was initiated, but could not be continued due to marked and fast clinical deterioration. The authors call attention to the difficulty of early diagnosis of MTVT due to a nonspecific clinical picture, the lack of action by the patient when the scrotal enlargement was first noticed, and the lack of tumor markers. Delayed diagnosis is definitely related to unfavorable prognosis.

Malignant mesotheliomas in spermatic cords: reports of two cases and a brief review of literature

Primary malignant mesothelioma (MM) of spermatic cord is extremely rare. We presented two malignant mesotheliomas involving the spermatic cords; one was primary, one secondary. The secondary one represented the direct involvement by a peritoneal MM. No occupational exposure to asbestos was identified in either patient. Both of them presented with a painless inguinal mass. Microscopically the primary MM was epithelioid type with tumor nests infiltrating adjacent adipose tissue, while the secondary MM grew in mixed type. No tumor necrosis was seen in the primary MM, while extensive necrosis was seen in the secondary one. Rare mitotic figure was seen in the primary MM while the mitosis in the secondary tumor was brisk, and with atypical mitosis. Immunohistochemically the tumor cells were positive for calretinin and CK5/6 and negative for BER-EP4 and BRST3 in both cases. The reported cases of primary MM from spermatic cord in English literature were briefly reviewed.

Malignant mesothelioma of the tunica vaginalis: presenting with intermittent scrotal pain and hydrocele

Paratesticular mesotheliomas are very rare tumors. In this paper, we present the management of a 38-year-old male patient with paratesticular malignant mesothelioma who was initially misdiagnosed and treated as recurrent epididymitis. After the final pathology report defining paratesticular mesothelioma during scrotal exploration, he underwent radical orchiectomy and hemiscrotal excision as a complementary, secondary procedure. His metastatic workup did not show any dissemination. Therefore, he did not receive any adjuvant treatment and remained disease-free for more than 2 years.

Perineal and colonic metastases in two cases of malignant mesothelioma

Two patients with rare sites of metastatic pleural mesothelioma are presented and the literature on similar cases is examined. One patient developed colonic metastases from a sarcomatoid mesothelioma. Another patient with epithelioid mesothelioma developed perineal metastases.

Transforming growth factor beta 1 induces tight junction disruptions and loss of transepithelial resistance across porcine vas deferens epithelial cells

Epithelial cells lining the male excurrent duct contribute to male fertility by employing a number of physiological mechanisms that generate a luminal microenvironment conducive to spermatozoa maturation and storage. Among these mechanisms, male duct epithelia establish intercellular tight junctions that constitute a barrier to paracellular diffusion of water, solutes, large molecules, and cells. Mechanisms regulating the male duct epithelial barrier remain unidentified. Transforming growth factor beta (TGFB) is a regulatory cytokine present in high concentrations in human semen. This study examined whether TGFB has any effects on epithelial function exhibited by primary cultures of porcine vas deferens epithelia. TGFB1 exposure caused a 70%-99% decrease in basal transepithelial electrical resistance (R(TE), a sensitive indicator of barrier integrity), while a significant decrease in anion secretory response to forskolin was detected at the highest levels of TGFB1 exposure employed. SB431542, a selective TGFB receptor I (TGFBR1) inhibitor, prevented decreases in barrier function. Results also demonstrated that TGFB1 exposure modifies the distribution pattern of tight junction proteins occludin and claudin 7. TGFBR1 is localized at the apical border of the native porcine vas deferens epithelium. Pharmacological inhibition of mitogen-activated protein kinase (MAPK) 11 (also known as p38-MAPK) did not alter the effect of TGFB1 on R(TE) significantly. These data suggest that epithelia lining the vas deferens are subject to disruptions in the physical barrier if active TGFB becomes bioavailable in the luminal fluid, which might be expected to compromise fertility.

Mesothelioma of tunica vaginalis testis and asbestos exposure

Study Type - Therapy (case series). Level of Evidence 4. What's known on the subject? and What does the study add? Mesothelioma of the tunica vaginalis testis is a rare tumour. From 2000 to 2010, 13 mesothelioma of the tunica vaginalis testis cases were reported in the most populated and industrialized region in Italy. Asbestos exposure was documented in two-thirds of these cases.

OBJECTIVE

• To describe cases of mesothelioma of the tunica vaginalis testis (MTVT) recorded in the Lombardy Mesothelioma Registry between 2000 and 2010.

METHODS

• The Lombardy Mesothelioma Registry, established in 2000, collects data regarding all incident cases of mesothelioma of the pleura, peritoneum, pericardium and tunica vaginalis testis that have been diagnosed in the population of the Lombardy region. • These data include a detailed clinical report and a complete occupational history for each MTVT patient, with the latter including details of the industrial sector involved, the patient's job, and the specific tasks performed. To address the potential for asbestos exposure outside the work environment, the residential history, lifestyle habits and hobbies of the patient, as well as job information for all subjects living with the patient, are also collected. • Records were reviewed and discussed by a panel of experts.

RESULTS

• Thirteen cases of MTVT were reported between 2000 and 2010. • The age-standardized incidence rate of MTVT for the Lombardy region of Italy is 0.2 cases per million individuals/year. • Asbestos exposure was documented in 8 of the 12 (67%) interviewed cases.

CONCLUSIONS

• Asbestos exposure was associated with a higher proportion of MTVT cases than previously reported in the literature. These results confirm the aetiological role for asbestos in the pathogenesis of MTVT. • The results of this study also highlight the importance of obtaining detailed occupational histories and lifestyle habits from patients, particularly by trained interviewers.

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.

Malignant mesothelioma of the spermatic cord

Primary tumors arising from the spermatic cord are very rare. Mesothelioma derives from the mesothelial cells lining the serous membrane, such as the pleura, peritoneum, and tunica vaginalis of testis. Paratesticular malignant mesothelioma (MM), which usually presents as a hydrocele or intrascrotal mass, accounts for 0.3% to 1.4% of MMs. MMs of the spermatic cord account for less than 10% of paratesticular MMs. We report a case of MM of the spermatic cord in a 65-year-old man who primarily presented to the hospital with a left inguinal mass. Following the diagnosis after surgery, he was found to have a contralateral right inguinal mass and died in 6 months. Despite their rare occurrence in the spermatic cord, MMs need to be suspected, especially in patients with a history of asbestos exposure.