Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT 05401.
Department of Pathology, Duke University Medical Center, Durham, NC, 27710.
Hum Pathol. 2019 Oct;92:48-58. doi: 10.1016/j.humpath.2019.07.009. Epub 2019 Aug 1.
Malignant mesothelioma (MM) arising from the serosal membranes of the tunica vaginalis testis (TVT) is rare. Most examples in the published medical literature are individual case reports. This study presents the clinicopathological findings of mesothelioma of the TVT in one of the largest series to date. Individuals with mesothelioma of the TVT were identified from a database of more than 4000 mesothelioma cases, and their clinicopathological features were recorded. Eighteen men with MM and 2 with well-differentiated papillary mesothelioma of the TVT were identified, which represented 0.6% of males with mesothelioma in study population. The median age at diagnosis was 72 years (range, 32-85 years). A neoplasm was not suspected preoperatively in 12 of the 17 (71%) men whose clinical presentation was known, 7 of whom presented with hydrocele and 5 with inguinal hernia. The other 5 had a clinically recognized mass. Seven of the men underwent herniorrhaphy; 7, radical orchiectomy; 3, hydrocelectomy; and 3, paratesticular mass biopsy or excision as the initial diagnostic procedure. Twelve of the MM cases were epithelioid and 6 were biphasic. Among the 6 men with MM who had ≥6 months of follow-up, 1 was alive with no evidence of disease at 6 months, and 5 were known to have died of disease 8-74 months (median = 31.5 months) following diagnosis. Three men with MM had received either chemotherapy or radiation therapy. Of the 2 men initially diagnosed with well-differentiated papillary mesothelioma, 1 was alive without evidence of disease 5 years after diagnosis, while the other had findings more compatible with MM with peritoneal involvement 2 years following initial diagnosis. In 15 of the 18 cases of MM (83%), there was documented occupational or paraoccupational exposure to asbestos, the average duration of which was 33 years (range, 2-46 years). Information regarding the presence or absence of pleural plaques was available in 5 of the MM cases, and pleural plaques had been found in 4. Lung tissue was not available for fiber analysis in any of the cases. One additional case originally diagnosed at another institution as MM of the TVT was reclassified as adenocarcinoma following performance of additional immunohistochemical testing. TVT is a rare site of MM, the diagnosis of which is often unsuspected preoperatively. Like its counterparts at other serosal sites, MM of the TVT is an aggressive tumor with a poor prognosis that evidence would suggest is etiologically associated with asbestos in at least some cases.
睾丸鞘膜的恶性间皮瘤（MM）很少见。发表的医学文献中大多数病例为个案报告。本研究报道了迄今最大系列之一的睾丸鞘膜间皮瘤的临床病理发现。从超过 4000 例间皮瘤病例的数据库中确定了 TVT 间皮瘤患者，并记录了他们的临床病理特征。在研究人群中，18 名男性患有 MM，2 名患有分化良好的 TVT 乳头状间皮瘤，占男性间皮瘤的 0.6%。诊断时的中位年龄为 72 岁（范围，32-85 岁）。已知 17 名男性中的 12 名（71%）术前未怀疑存在肿瘤，其中 7 名表现为鞘膜积液，5 名表现为腹股沟疝。另外 5 名有临床可识别的肿块。7 名男性接受了疝修补术；7 名男性接受了根治性睾丸切除术；3 名男性接受了鞘膜积液切除术；3 名男性接受了睾丸旁肿块活检或切除术作为初始诊断程序。12 例 MM 为上皮样，6 例为双相性。在 6 名有≥6 个月随访的 MM 男性中，1 名在 6 个月时无疾病证据存活，5 名在诊断后 8-74 个月（中位 31.5 个月）时已知死于疾病。3 名 MM 男性接受了化疗或放疗。最初诊断为分化良好的乳头状间皮瘤的 2 名男性中，1 名在诊断后 5 年无疾病证据，而另 1 名在初始诊断后 2 年发现与腹膜受累更相符的 MM。在 18 例 MM 病例中（83%），有记录的职业或职业相关的石棉暴露，平均持续时间为 33 年（范围，2-46 年）。在 5 例 MM 病例中可获得胸膜斑存在或不存在的信息，4 例存在胸膜斑。在任何病例中都没有肺组织进行纤维分析。在另一家机构最初诊断为 TVT 间皮瘤的 1 例病例，在进行了额外的免疫组织化学检测后，重新分类为腺癌。TVT 是 MM 的罕见部位，术前通常未怀疑其存在。与其他浆膜部位的 MM 一样，TVT 间皮瘤是一种侵袭性肿瘤，预后不良，有证据表明，至少在某些情况下，它与石棉病因学相关。
