Malignant pleural mesothelioma mimicking the intrapulmonary growth pattern of epithelioid hemangioendothelioma

Our plain-English summary of Malignant pleural mesothelioma mimicking the intrapulmonary growth pattern of epithelioid hemangioendothelioma, by Y. Muramatsu, K. Isobe, K. Sugino, et al (Pathology International, 2014).

The study

• Authors: Y. Muramatsu, K. Isobe, K. Sugino, A. Kinoshita, T. Wada, S. Sakamoto, Y. Takai, F. Sato, Y. Hata, M. Wakayama, K. Sibuya, T. Uekusa, A. Iyoda, S. Homma
• Journal: Pathology International
• Published: 2014;64(7):358-60
• Type of article: Case report, Letter
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This letter to the editor described one patient: a 72-year-old Japanese man hospitalized for worsening breathlessness on exertion, with fluid around the right lung. He was a heavy smoker and had been exposed to asbestos at his job for over 30 years. The fiber type was not stated. CT scans showed focal pleural thickening and a 15 mm nodule in the lower right lung. Tests of the pleural fluid found no evidence of cancer. Biopsies taken during thoracoscopic surgery showed biphasic malignant pleural mesothelioma, which contains both epithelioid and spindle-shaped cells. The lung nodule was also biphasic mesothelioma, but part of it closely resembled epithelioid hemangioendothelioma (EHE), a rare blood-vessel tumor. Stains for blood-vessel markers were negative in that area. The authors suggested there may be a close relationship between a sarcomatoid component and this EHE-like pattern. They stated that thoracoscopic biopsy with multiple, extensive samples is essential for diagnosis. The percentages the letter mentions come from earlier studies. Because this report describes a single person, it cannot show how often this pattern occurs.

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 (letter to the editor) describing one patient
• Who was studied: One 72-year-old Japanese man hospitalized for progressive shortness of breath on exertion, with right pleural effusion; treated at Toho University Omori Medical Center, Tokyo (dates not given)
• Exposure: Occupational asbestos exposure for over 30 years (fiber type and job not specified). He was also a heavy smoker with a smoking index of 1500.
• Main results:
  • After fluid drainage, chest CT in this patient showed focal pleural thickening near the vertebral body and a 15 mm peripheral nodule inside the right lung (posterior basal segment, S10)
  • Cell and bacterial tests of the patient's pleural fluid showed no evidence of malignancy
  • The pleural fluid had a CYFRA level of 6.7 ng/mL and a hyaluronic acid level of 28 200 μg/L
  • The biopsy of the parietal pleura (chest-wall lining) showed features typical of biphasic malignant pleural mesothelioma
  • Part of the lung nodule (hyalinized stroma) looked very similar to epithelioid hemangioendothelioma under high power
  • The EHE-like area showed weak expression of the mesothelial markers WT-1 and D2-40 and no expression of the endothelial (blood-vessel) markers CD34 and von Willebrand factor
  • The final diagnosis was biphasic malignant pleural mesothelioma with a growth pattern inside the lung that mimicked EHE
  • The authors noted that the thickened visceral pleura next to the EHE-like nodule was mainly sarcomatoid. They suggested a possible close relationship between a sarcomatoid component and an EHE-like growth pattern.
• The authors' conclusion: The authors concluded that thoracoscopic biopsy, with collection of multiple, extensive biopsies, is essential for diagnosis, as indicated in European guidelines

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Epithelioid.

Related studies

• CAMTA1 immunostaining is not useful in differentiating epithelioid hemangioendothelioma from its potential mimickers — Z. Yusıflı, K. Kösemehmetoğlu (2014)
• Epithelioid hemangioendothelioma of the pleura: clinical and radiologic features — E.J. Crotty, H.P. McAdams, et al. (2000)
• Biphasic malignant mesothelioma with epithelioid and sarcomatoid components (dedifferentiated mesothelioma) and intrapulmonary growth: a rare entity mimicking desquamative interstitial pneumonia — J. Laforga, A. Gonzalez Garcia (2020)
• Primary pleural epithelioid hemangioendothelioma mimicking as a posterior mediastinal tumor — J. Wethasinghe, J. Sood, et al. (2015)
• Primary epithelioid haemangioendothelioma of the peritoneum: an unusual mimic of diffuse malignant mesothelioma — R.L. Attanoos, N.S. Dallimore, et al. (1997)
• Primary pleural epithelioid haemangioendothelioma with metastases to the skin. A case report and literature review — M. Al-Shraim, B. Mahboub, et al. (2005)

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