Diagnostic Differentiation Between Two Rare Entities-Metastatic Peritoneal Mesothelioma With Duodenal Involvement and Duodenal Synovial Sarcoma: A Case Report

Our plain-English summary of Diagnostic Differentiation Between Two Rare Entities-Metastatic Peritoneal Mesothelioma With Duodenal Involvement and Duodenal Synovial Sarcoma: A Case Report, by B. Haueisen Figueiredo Zwetkoff, F. Maluf-Filho, F.E. Venco, et al (Curēus, 2024).

The study

• Authors: B. Haueisen Figueiredo Zwetkoff, F. Maluf-Filho, F.E. Venco, R. Blasbalg, E. Sobroza de Mello, M.F. de Almeida Barros
• Journal: Curēus
• Published: 2024;16(11):e74764
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

This case report highlights the diagnostic challenges in distinguishing between metastatic peritoneal mesothelioma with duodenal involvement and synovial sarcoma of the duodenum, two rare and complex entities. A 59-year-old woman presented with nonspecific abdominal symptoms, and imaging revealed a heterogeneous lesion between the right hepatic lobe and duodenum. Endoscopic ultrasound-guided biopsy and subsequent histopathological analysis initially suggested synovial sarcoma, but further examination, including a FISH assay, confirmed the diagnosis of malignant peritoneal mesothelioma. This case underscores the importance of integrating detailed medical history, imaging, and advanced diagnostic techniques to achieve an accurate diagnosis in rare conditions. Early and precise identification of such diseases is crucial for appropriate therapeutic management and has significant implications for patient prognosis.

Copyright © 2024, Haueisen Figueiredo Zwetkoff et al.

In plain English

This case report described a 59-year-old woman with no history of asbestos exposure who had about 60 days of abdominal pain, bloating and distension. An MRI scan showed a mass of about 6.0 x 5.0 cm between the liver and the duodenum, and endoscopy found a duodenal ulcer. Biopsies were first interpreted as a high-grade biphasic sarcoma, suggesting synovial sarcoma of the duodenum. At surgery, the tumor was adherent to the liver and had spread through the peritoneum and omentum, so curative removal was not possible. Surgical specimens were positive for mesothelial markers (calretinin, WT-1 and D2-40). A FISH genetic test found no SS18/SYT gene rearrangement, which is present in almost all synovial sarcomas. The diagnosis was changed to malignant peritoneal mesothelioma. After three cycles of chemotherapy failed, she received immunotherapy, and an MRI three months after diagnosis showed the lesion reduced from 2750cc to 425cc. The authors concluded that diagnosis required correlating medical history, imaging and pathology, sometimes with FISH testing.

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
• Who was studied: One 59-year-old woman with about 60 days of abdominal symptoms; the authors are based at institutions in São Paulo, Brazil
• Exposure: The patient had no history of asbestos exposure; no fiber type or occupational exposure was reported
• Main results:
  • MRI showed a heterogeneous mass of approximately 6.0 x 5.0 cm between the right hepatic lobe and the duodenum
  • Endoscopic ultrasound-guided and endoscopic biopsies were first read as a high-grade biphasic sarcoma
  • At laparotomy the tumor was adherent to the liver, with peritoneal implants and 'omental cake', so curative resection was not possible
  • Surgical specimens showed a malignant biphasic tumor positive for mesothelial markers calretinin, WT-1 and D2-40/podoplanin
  • FISH found no SS18/SYT gene rearrangement, and together with immunohistochemistry this confirmed malignant peritoneal mesothelioma
  • After treatment failure with three cycles of chemotherapy, the patient had 13 cycles of checkpoint blockade immunotherapy. MRI three months after diagnosis showed the lesion reduced from 2750cc to 425cc, and the patient remained clinically stable
• The authors' conclusion: The authors concluded that advanced diagnostic methods contributed little on their own. In their view, accurate diagnosis required good correlation of medical history, imaging and histology, sometimes with further testing such as FISH.

Topics

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Synovial Sarcoma, Ultrasound, Biopsy, Fluorescence In Situ Hybridization (FISH), Prognosis.

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