|Year : 2019 | Volume
| Issue : 8 | Page : 167-169
Malignant mesothelioma of tunica vaginalis without any risk factors: An uncommon case
Chirag B Punatar, Kunal K Jadhav, Vikash Kumar, Sharad N Sagade
Department of Urology, P.D. Hinduja National Hospital and Medical Research Centre, Mumbai, Maharashtra, India
|Date of Web Publication||22-Mar-2019|
Dr. Chirag B Punatar
Department of Urology, P.D. Hinduja National Hospital and Medical Research Centre, Veer Savarkar Marg, Mahim West, Mumbai - 400 016, Maharashtra
Source of Support: None, Conflict of Interest: None
Malignant mesothelioma (MM) of the tunica vaginalis (TV) is a rare tumor. It is seen in elderly patients, with painless scrotal swelling being the most common presentation. The exact etiology is unknown; a few risk factors have been suggested. Here, we present an uncommon case of MM of TV without any known predisposing factors. We also discuss the possible risk factors, clinical presentation, pathological features and the difficulties in diagnosis, and management of this rare malignancy.
Keywords: Asbestos exposure, hydrocele, malignant mesothelioma, radical inguinal orchidectomy, scrotal swelling
|How to cite this article:|
Punatar CB, Jadhav KK, Kumar V, Sagade SN. Malignant mesothelioma of tunica vaginalis without any risk factors: An uncommon case. J Can Res Ther 2019;15, Suppl S1:167-9
| > Introduction|| |
Malignant mesothelioma (MM) commonly affects the pleura, pericardium, or peritoneum. MM arising from the tunica vaginalis (TV) is rare. Possibly, it is underdiagnosed and underreported. The etiopathogenesis of this rare tumor is not fully known. Because of lack of characteristic clinicoradiological features and reliable tumor markers, preoperative diagnosis is very difficult. Through our case report, we highlight the importance of pathological examination of the hydrocele sac and appropriate surgical treatment in the management of this uncommon malignancy.
| > Case Report|| |
A 44-year-old male patient presented with 3 months history of painless, gradually enlarging right-sided scrotal swelling. Apart from hypertension, his medical history was unremarkable. He denied any history of trauma. Clinical examination suggested a right-sided hydrocele. The left scrotum was normal. Rest of the physical examination was normal. A working diagnosis of the right-sided hydrocele was made. All routine investigations were normal. Sonography and color Doppler of scrotum was suggestive of the right-sided hydrocele with clear fluid and normal right testis [Figure 1]. He underwent partial excision of the hydrocele sac. Intraoperatively, the sac appeared grossly normal and the fluid was clear. The histology showed MM of epithelial type [Figure 2]. Immunohistochemistry showed coexpression of calretinin, WT1 protein, and cytokeratin [Figure 3]. On subsequent questioning, he denied any exposure to asbestos or related compounds. A whole body positron emission tomography-computed tomography (PET-CT) scan showed no uptake elsewhere except in the region of the right hemiscrotum [Figure 4]. He subsequently underwent an inguinal orchidectomy with hemiscrotectomy. The histology showed a tiny focus of residual disease (<1 mm) in the residual sac. All margins were negative. A medical oncology opinion was sought, and it was decided to keep the patient under periodic follow-up. At 18 months of follow-up, the patient is free of disease.
|Figure 1: Sonography image showing a normal right testis and increased vascularity of the right epididymis|
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|Figure 2: Low-power magnification (×40) using hematoxylin-eosin staining showed a tubular pattern of tumor infiltrating deep into the thickened tunica. High power (×100) is shown as an inset in the left bottom corner|
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|Figure 3: Immunohistochemistry showing staining with cytokeratin, WT1 protein, and calretinin. The staining with calretinin is intense confirming the diagnosis|
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|Figure 4: Positron emission tomography-computed tomography images showing an abnormal uptake in the area of right hemiscrotum|
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| > Discussion|| |
Mesotheliomas are rare tumors arising from the lining of coelomic cavities. Pleura is the most common site. TV is a rare site, with <250 cases reported in the literature; however, considering the high incidence of hydrocele and the extreme rarity of this disease, it is possible that this disease is underreported. It commonly affects males between 55 and 75 years of age. However, cases have also been reported in younger adults and children.
The etiopathogenesis is not fully known. Exposure to asbestos is a hypothesized predisposing factor; however, is seen in only about 35% of cases. The exact mechanism by which asbestos predisposes is unknown. Direct effect of the deposited asbestos fibers and chronic irritation of the tissues have been postulated as possible mechanisms. A genetic association between HLA-W27 and the severity of the disease has been suggested, but not proven. Chronic immunosuppression has also been postulated. Recurrent epididymitis has also been postulated to predispose by causing chronic inflammation. Trauma, viral infection with SV40, radiation exposure, and inguinal hernia and/or its surgical correction have all been postulated, but none proven. In our patient, none of the proposed risk factors was present.
Painless scrotal swelling is the most common presenting symptom and often the working diagnosis is hydrocele. A study found that hydrocele was the most common preoperative diagnosis in about half of the cases, followed by suspicious testicular mass in a third. Since the clinical presentation closely mimics a hydrocele, a correct preoperative diagnosis is difficult, and rarely reported. Ultrasound and color Doppler imaging of the scrotum are valuable diagnostic aids, helping primarily to rule out other differential diagnosis. Irregular thickening of the tunica and extratesticular masses on ultrasound have been reported to be associated with MM. The tumor has been reported to show both hypo and hypervascularity on color Doppler, thus limiting the use of this modality. There are no characteristic findings, and as in our case, these investigations may be normal also. Most cases are diagnosed intraoperatively or postoperatively, based on histological findings, and our case was no exception.
MM of TV are of three histological subtypes as follows: epithelioid (about 75%), sarcomatoid (rarest), and biphasic. Immunohistochemistry is an important adjunct to establishing the diagnosis with coexpression of calretinin and cytokeratin 5/6 being a valuable finding. Imaging of the thoracic and abdominal cavities should always be done in all patients, once the diagnosis of MM is made, to confirm or exclude the presence of metastases. In our case, we did whole body PET-CT scan.
Surgery is the only curative treatment. As most cases are diagnosed intraoperatively or at final histology, a second procedure is usually required to excise the remaining tissue. Radical inguinal orchidectomy and hemiscrotectomy is the recommended surgical treatment. Excision of the hydrocele sac only is associated with a much higher percentage of recurrence compared to radical orchidectomy (35% vs. 10%). Retroperitoneal nodes are involved more commonly than other nodes. The necessity for inguinal or iliac lymph node dissection as primary therapy remains controversial. A limited lymph node dissection is only recommended in cases with clinically involved nodes.
The role of adjuvant radiotherapy and chemotherapy is controversial. Plas et al. believe that adjuvant radiotherapy should be considered for patients with locally advanced disease following tumor resection with safe margins. Most of the patients with advanced disease are treated with chemotherapy. A combination of both has been tried in a limited number of cases with promising results.
Prognosis depends on many factors. Younger patients, those with organ-confined disease, and those without exposure to asbestos do significantly better than others. The tumor recurrence is frequently noted, with up to 60% of the recurrences occurring in the first 2 years. The tumor recurrence is generally associated with tumor progression and metastatic dissemination, though isolated local tumor recurrences have also been reported.
To conclude, MM should be kept in mind, as a possible differential in patients presenting with hydrocele, particularly if they are elderly or if preoperative ultrasound or color Doppler show any suspicious features. Histological examination of the hydrocele sac is extremely essential to confirm the diagnosis. Once the diagnosis is established, appropriate surgery is crucial in the management of the nonmetastatic disease.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
The authors would like to acknowledge the National Health and Education Society (the work was carried out at Hinduja Hospital, Mumbai). The efforts of Dr R B Deshpande for providing the histological images are acknowledged.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]