Primary pulmonary epithelioid sarcoma: a case report

Our plain-English summary of Primary pulmonary epithelioid sarcoma: a case report, by E. Mizutani, R. Morita, K. Abe, et al (Journal of Medical Case Reports, 2021).

The study

• Authors: E. Mizutani, R. Morita, K. Abe, M. Kodama, S. Kasai, Y. Okochi, N. Motoi
• Journal: Journal of Medical Case Reports
• Published: 2021;15(1):330
• Type of article: Case report
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Epithelioid sarcoma most frequently occurs in the dermal or subcutaneous area of the distal extremities. To date, there have been three cases of primary pulmonary epithelioid sarcoma reported. We report a case of epithelioid sarcoma that is considered a primary lung tumor.

Case Presentation: A 65-year-old asymptomatic Asian male patient underwent chest radiography during a routine health examination, and an abnormal mass was detected. His past medical history was unremarkable. He smoked 40 cigarettes every day and had slightly obstructive impairment on spirometry. He worked as an employee of a company and had no history of asbestos exposure. He underwent partial resection of the right lung by thoracoscopy. A histological examination of the tumor revealed a cellular nodule of epithelioid and spindle-shaped cells. Some of the tumor cells displayed rhabdoid features and reticular arrangement in a myxomatous stroma. Immunohistochemically, the tumor cells were positive for vimentin, smooth muscle actin (SMA), CD34, and epithelial membrane antigen (EMA); loss of the BAF47/INI1 protein in the tumor cells was also confirmed. A diagnosis of epithelioid sarcoma was established. Careful screening by whole-body positron emission tomography for another primary lesion after surgery did not detect any possible lesion. He had no cutaneous disease.

Conclusion: To our knowledge, this is the fourth case of a proximal-type epithelioid sarcoma considered as a primary lung tumor.

In plain English

This case report from Japan described one man whose lung tumor was diagnosed as epithelioid sarcoma, a rare soft-tissue cancer that usually arises in or under the skin of the far ends of the limbs. The 65-year-old Asian man had no symptoms. A mass was found on a chest X-ray at a routine health check. He had smoked two packs of cigarettes a day for 45 years, worked as a company employee, and had no history of asbestos exposure. Of two nodules in his right lung, the larger grew from 1.5 cm to 2.0 cm over 3 months. Both were removed by thoracoscopic surgery. The larger nodule was diagnosed as epithelioid sarcoma based on microscopy, staining tests and loss of the BAF47/INI1 protein. The smaller nodule was a hamartoma. A whole-body PET scan after surgery found no other tumor, and an X-ray at 4 months showed no recurrence. The authors concluded that this was, to their knowledge, the fourth case of proximal-type epithelioid sarcoma considered a primary lung tumor. They noted that telling a primary tumor from a spread tumor is difficult.

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 65-year-old asymptomatic Asian man in whom a lung mass was found on routine chest radiography. The authors are from Tokyo Yamate Medical Center and the National Cancer Center Hospital, Tokyo, Japan. Dates of care are not given.
• Exposure: No asbestos exposure. The patient had no history of asbestos exposure, worked as a company employee, and smoked two packs of cigarettes per day for 45 years.
• Main results:
  • Computed tomography showed two nodules in the right lung: 1.5 cm in the right upper lobe and 0.5 cm in the right lower lobe.
  • After 3 months the larger nodule had grown to 2.0 cm; the smaller nodule was unchanged.
  • The patient had wedge resection of the right upper and lower lobes by thoracoscopy and was discharged without complications.
  • The upper-lobe tumor was made up of epithelioid and spindle-shaped cells.
  • Tumor cells stained positive for vimentin, smooth muscle actin, CD34 and EMA, and had lost the BAF47/INI1 protein. The lesion was diagnosed as epithelioid sarcoma.
  • The right lower lobe nodule was diagnosed as a hamartoma.
  • A whole-body PET scan on day 40 after surgery showed no abnormal uptake.
  • A chest X-ray at 4 months showed no recurrence. The patient was treated with surgery alone, without adjuvant chemotherapy.
• The authors' conclusion: The authors concluded that, to their knowledge, this was the fourth case of proximal-type epithelioid sarcoma considered a primary lung tumor. They based the judgment that it was primary on the PET findings and a dermatologist's examination.
• Limitations the authors state:
  • The authors state that it is difficult to distinguish a primary lung tumor from a metastasis.
  • The authors state that, because the tumor is rare, there are limited data on how to manage it.
  • Follow-up was short, and the authors state that the patient needs careful follow-up.

Topics

Medical terms in this study, explained in our Lexicon: Epithelioid, Sarcoma, Spirometry, Asbestos Exposure, Thoracoscopy, Spindle Cell, Rhabdoid, CD34.

Related studies

• A case of pleural epithelioid sarcoma of proximal type presenting as malignant pleural mesothelioma — G.A. Madsen, T.R. Rasmussen, et al. (2013)
• Epithelioid sarcoma. A clinical and pathologic study of nine cases — H. Santiago, L.K. Feinerman, et al. (1972)
• Metastatic proximal epithelioid sarcoma in pleural effusion: cytopathologic findings and differential diagnosis — H. Guan, F. Haque, et al. (2013)
• Nuclear Brachyury Expression Is Consistent in Chordoma, Common in Germ Cell Tumors and Small Cell Carcinomas, and Rare in Other Carcinomas and Sarcomas: An Immunohistochemical Study of 5229 Cases — M. Miettinen, Z. Wang, et al. (2015)
• The effect of internalizing human single chain antibody fragment on liposome targeting to epithelioid and sarcomatoid mesothelioma — A.K. Iyer, Y. Su, et al. (2011)
• Epithelioid angiosarcoma of the pleura: a case report — M.S. Roh, J.Y. Seo, et al. (2001)

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