Extra-gastrointestinal stromal tumor presenting as a huge peritoneal mass and mimicking as mesothelioma - A case report

Our plain-English summary of Extra-gastrointestinal stromal tumor presenting as a huge peritoneal mass and mimicking as mesothelioma - A case report, by D. Ghartimagar, A. Ghosh, M.K. Shrestha, et al (International Journal of Surgery Case Reports, 2021).

The study

• Authors: D. Ghartimagar, A. Ghosh, M.K. Shrestha, H. Batajoo, O.P. Talwar
• Journal: International Journal of Surgery Case Reports
• Published: 2021;78:351-355
• Type of article: Case report
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction And Importance: Extra-gastrointestinal stromal tumors are group of soft tissue neoplasm, which originates outside the gastrointestinal tract comprising of less than 5% of the total gastrointestinal stromal tumors.

Case Presentation: A 67 years old male came with a history of vague abdominal pain, discomfort and loss of appetite. Per abdominal examination showed a palpable firm mass which was filling both the flanks. Radiological imaging revealed a large abdomino-pelvic mass with central necrotic areas. Exploratory laparotomy was done and the mass was excised intact from the sigmoid mesocolon. Histopathological diagnosis was given as extra-gastrointestinal stromal tumors.

Clinical Discussion: Extra-gastrointestinal stromal tumor was first described by Miettinen et al. in 1999. The tumor can arise from the pleura, omentum, mesentery, retroperitoneum and prostate. The clinical presentation of the tumor depends on its location and the size of tumor. Patients with these tumors present with abdominal pain, followed by abdominal mass and distention. These tumors show pathological, immunohistochemical and molecular biological characters similar as that of gastrointestinal stromal tumor.

Conclusion: Extra-gastrointestinal stromal tumor is a rare tumor and can reach to a considerable large size before presenting with clinical symptoms especially if the tumor arises from the mesocolon. IHC study plays an important role to reach to the final diagnosis as the tumor can mimic mesothelioma in routine staining.

Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.

In plain English

This case report described one patient: a 67-year-old male farmer from Pokhara, Nepal, with vague abdominal pain, discomfort and reduced appetite for 2 months. The article states he was a non-smoker with no past history of exposure to chemicals or asbestos. A large firm mass filled both sides of his abdomen. A CT scan showed a large abdomino-pelvic mass with dead (necrotic) areas, and a chest X-ray showed no pleural mass. Surgeons removed the mass intact from the sigmoid mesocolon; it measured 28 × 23 × 16 cm. Under routine staining, the tumor was thought to be a sarcomatous variant of mesothelioma. Special stains (immunohistochemistry) showed the tumor cells were positive for CD117 and CD34 and negative for S100 and SMA, and the final diagnosis was extra-gastrointestinal stromal tumor. He was referred to oncology. The authors concluded that this rare tumor can mimic mesothelioma on routine staining and that immunohistochemistry plays an important role in reaching the final diagnosis.

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 (single patient)
• Who was studied: One 67-year-old male farmer of Brahmin ethnicity from the Sub-Himalayan valley of Pokhara, Nepal, seen in a surgical outpatient department
• Exposure: The article reports no asbestos exposure. The patient was a non-smoker with no past history of exposure to chemicals or asbestos.
• Main results:
  • The patient had a palpable huge firm mass filling both flanks.
  • Chest X-ray showed no pleural mass or bony lesion.
  • The mass was surgically excised intact from the sigmoid mesocolon and measured 28 × 23 × 16 cm.
  • On routine H&E staining, the tumor was thought to be a sarcomatous variant of mesothelioma.
  • Immunohistochemistry showed the tumor cells were positive for CD117 and CD34 and negative for S100 and SMA, confirming extra-gastrointestinal stromal tumor.
  • The tumor showed areas of necrosis and atypical mitoses of 3 per 50 high-power fields.
  • After surgery, the patient was referred to the oncology department.
• The authors' conclusion: The authors concluded that extra-gastrointestinal stromal tumor is rare and that immunohistochemistry plays an important role in reaching the final diagnosis, because the tumor can mimic mesothelioma on routine staining.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Neoplasm, Laparotomy, Pleura, Omentum, Mesentery, Retroperitoneum.

Related studies

• Primary omental gastrointestinal stromal tumor (GIST) — T. Todoroki, T. Sano, et al. (2007)
• Expression of neural cell adhesion molecule L1 (CD171) in neuroectodermal and other tumors: An immunohistochemical study of 5155 tumors and critical evaluation of CD171 prognostic value in gastrointestinal stromal tumors — S. Inaguma, Z. Wang, et al. (2016)
• An entity that should be kept in mind: Synchronous gastrointestinal stromal tumor encountered in resection materials obtained for the detection of intra-abdominal malignancies — S.S. Erhan, G. Kulduk, et al. (2023)
• Extragastrointestinal Stromal Tumor Presenting as Omental Cyst — A. Monabati, M. Safavi, et al. (2016)
• A rare case of a huge malignant pleural mesothelioma presenting in the posterior mediastinum — Y. Mori, C. Kato, et al. (2024)
• Peritoneal mesothelioma presenting as an adnexal mass — R.A. Komorowski, D.H. Bobert (1975)

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