Ultrasonographic misdiagnosis of multicystic mesothelioma of the omentum: A case report

Our plain-English summary of Ultrasonographic misdiagnosis of multicystic mesothelioma of the omentum: A case report, by Y. Diao, L. Chen, Z. Liu (Medicine, 2022).

The study

• Authors: Y. Diao, L. Chen, Z. Liu
• Journal: Medicine
• Published: 2022;101(36):e30441
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Rationale: Multicystic Mesothelioma (MM) is very rare and preoperative diagnosis is difficult.

Patient Concerns: We report a case of a 34-year-old man with solid abdominal cystic echo mass. Physical examination showed that the patient had a flat and soft abdomen without tenderness or rebound pain, no fluid wave tremor, and no obvious abdominal mass was touched. The patient complained of repeated abdominal distention with nausea for 5 days. Sonographic examination suspected pseudomyxoma peritoneum.

Diagnosis: Conventional ultrasound examination showed a cystic solid echo mass in the right abdominal cavity of the patient, with uneven internal echo and honeycomb change, and clear boundary with surrounding organs. Color Doppler suggested that the blood flow in the mass was not obvious. Contrast-enhanced computed tomography of the abdomen revealed hypodensity foci in hepatic and renal crypts and right paracolic sulcus.

Interventions: Laparoscopic resection of the mass was performed, and the postoperative pathological findings were polycystic mesothelioma (greater omentum).

Outcomes: After mass resection, all laboratory tests and abdominal ultrasound were normal, and abdominal distension and nausea disappeared.

Lessons: Improved ultrasound diagnosis of MM is useful for clinical decision-making.

Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.

In plain English

This was a case report from the ultrasound department of the First Affiliated Hospital of Nanchang University in China. It described one 34-year-old man who came to the hospital with five days of recurring abdominal swelling and nausea. Ultrasound showed a mass with both fluid-filled and solid parts on the right side of his abdomen, and pseudomyxoma peritoneum, a different condition, was considered. A contrast CT scan did not rule that out. Tumor markers (CEA, CA125, CA199 and AFP) were negative. The mass was removed by laparoscopic surgery. Tissue examination showed multicystic (also called polycystic) mesothelioma of the greater omentum. The removed tissue measured about 12 × 12 × 3.8 cm. Six months after surgery the man had no recurrence and no symptoms. The authors concluded that a mass inside the abdominal cavity should be considered for a diagnosis of polycystic mesothelioma when ultrasound shows it has many cysts, a "cheese sign" change, a thin capsule wall, and good sound transmission in its echo-free area. The article did not mention asbestos or any work or environmental exposure. It describes what happened to one patient only.

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 34-year-old man seen at the authors' hospital (First Affiliated Hospital of Nanchang University, Nanchang, China) with recurrent abdominal distention and nausea for 5 days. The date of presentation is not given.
• Exposure: Not reported. The article does not mention asbestos or any occupational or environmental exposure.
• Main results:
  • Before surgery, ultrasound showed a mass with uneven internal echo and a 'cheese sign' change, and color Doppler showed no obvious blood flow in the mass.
  • Based on the ultrasound, the mass was thought possibly to be pseudomyxoma peritoneum (the misdiagnosis in the title).
  • Contrast-enhanced CT showed low-density areas of undetermined nature and did not exclude pseudomyxoma peritoneum.
  • Preoperative tumor markers CEA, CA125, CA199 and AFP were negative.
  • The removed tumor was about 12 × 12 × 3.8 cm of grayish yellow tissue with vesicles about 0.1 to 1.5 cm across containing clear fluid.
  • Pathology after surgery diagnosed polycystic mesothelioma of the greater omentum.
  • Six months after the operation, the patient had no recurrence and no symptoms.
  • The authors stated that this patient's ultrasound features differed from those reported in the literature.
• The authors' conclusion: The authors concluded that an intraperitoneal polycystic mass on ultrasound with a cheese sign change, thin capsule wall and good acoustic transmission in the echo-free area should be considered for a diagnosis of intraperitoneal polycystic mesothelioma, and that histological evaluation is still necessary when it cannot be told apart from other cystic lesions.

Topics

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

Medical terms in this study, explained in our Lexicon: Misdiagnosis, Multicystic Mesothelioma (MCM), Omentum, Peritoneum, Ultrasound, Mesothelioma.

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