Malignant Mesothelioma Diagnosed From a Spermatic Cord Lesion After Inconclusive Thoracoscopy: A Case With Concomitant Pleural and Peritoneal Involvement

Our plain-English summary of Malignant Mesothelioma Diagnosed From a Spermatic Cord Lesion After Inconclusive Thoracoscopy: A Case With Concomitant Pleural and Peritoneal Involvement, by N. Hamazaki, S. Fujimoto, H. Jinno, et al (Curēus, 2026).

The study

• Authors: N. Hamazaki, S. Fujimoto, H. Jinno, N. Miyazaki, T. Masuda, H. Sato, Y. Kida, M. Yamamoto, K. Tada
• Journal: Curēus
• Published: 2026;18(5):e109236
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant mesothelioma typically arises in the pleura or peritoneum; however, involvement of the spermatic cord is extremely rare. Here, we report a case in which a definitive diagnosis was achieved through evaluation of a spermatic cord lesion after an inconclusive thoracoscopic biopsy. A 69-year-old man presented with dyspnea and right inguinal swelling. Imaging revealed a right pleural effusion, peritoneal nodules, and increased fluorodeoxyglucose uptake in the diaphragm and bilateral inguinal canals. Thoracoscopy under local anesthesia revealed a diaphragmatic mass; however, the biopsy specimen was insufficient for a definitive diagnosis. Subsequent right orchiectomy and laparoscopic examination revealed disseminated peritoneal nodules and a spermatic cord tumor. Histopathological examination of spermatic cord specimens showed invasive epithelioid malignant mesothelioma. This case highlights the limitations of small thoracoscopic biopsy specimens and underscores the importance of selecting the appropriate biopsy sites and techniques when mesothelioma is suspected.

Copyright © 2026, Hamazaki et al.

In plain English

This was a case report about one 69-year-old man with shortness of breath and a swelling in his right groin. According to the authors, he had no history of smoking or of exposure to occupational dust or asbestos. Scans showed fluid around the right lung, nodules in the abdominal lining (peritoneum), and abnormal activity near the diaphragm and in both groin canals. Thoracoscopy, a camera procedure in the chest, found a mass above the diaphragm, and a biopsy was taken from it. But the sample did not show invasion into deeper tissue, so mesothelioma could not be told apart from a non-cancerous reaction. Surgeons then removed the right testis and spermatic cord and looked inside the abdomen, finding many peritoneal nodules. The spermatic cord tumor showed clear invasion and was diagnosed as epithelioid malignant mesothelioma. The disease was judged unresectable. It was treated with cisplatin and pemetrexed and remained stable during follow-up. The authors concluded that surgical sampling from another lesion, such as the spermatic cord, can be crucial for a definitive diagnosis when biopsy specimens are limited.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (one patient)
• Who was studied: One 69-year-old man with dyspnea on exertion and a right-sided inguinal mass; the authors are from hospitals in Japan
• Exposure: No history of asbestos exposure was identified. The patient also had no history of smoking or occupational dust exposure
• Main results:
  • Fluid drawn from the chest was bloody with elevated hyaluronic acid, but cytology was negative for malignancy
  • Thoracoscopy under local anesthesia found a solitary mass above the diaphragm. Biopsy specimens showed papillary proliferation of tumor cells
  • The thoracoscopic biopsy did not show definitive stromal invasion, so it could not be distinguished from reactive mesothelial hyperplasia
  • Laparoscopy found multiple peritoneal nodules and ascitic fluid
  • The spermatic cord tumor showed clear invasion of surrounding fatty tissue, and the findings confirmed epithelioid malignant mesothelioma
  • The disease was considered unresectable. After cisplatin and pemetrexed it remained stable, with no new lesions during follow-up
• The authors' conclusion: The authors concluded that surgical sampling from an alternative lesion, such as the spermatic cord, can be crucial for a definitive diagnosis when biopsy specimens are limited, and that careful biopsy site selection is essential

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Spermatic Cord, Thoracoscopy, Pleura, Peritoneum, Dyspnea, Pleural Effusion, Diaphragm.

Related studies

• Treatment of malignant tumors of the spermatic cord: a study of 10 cases and a review of the literature — P.H. Blitzer, D.E. Dosoretz, et al. (1981)
• Tumors of the spermatic cord: a review of the literature and a report of a case of lymphangioma — A.A. el-Badawi, M.M. al-Ghorab (1965)
• Malignant mesothelioma of the spermatic cord — Y.J. Park, H.J. Kong, et al. (2011)
• Mesothelioma of spermatic cord: electron microscopic and histochemical characteristics of its mucopolysaccharides — P. Pizzolato, J. Lamberty (1976)
• Malignant Mesothelioma of Spermatic Cord in an Elderly Man With a History of Asbestos Exposure — A. D'Antonio, F. Mastella, et al. (2016)
• Malignant mesotheliomas in spermatic cords: reports of two cases and a brief review of literature — X. Meng, T.J. Guzzo, et al. (2013)

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