A new case study reports the successful diagnosis of peritoneal mesothelioma by endoscopic ultrasound (EUS)-guided tissue acquisition and fine-needle aspiration (FNA), a less invasive method than that commonly used. The case, with a description of the diagnosis, was published in Endoscopic Ultrasound, and titled “Malignant peritoneal mesothelioma diagnosed by EUS-guided tissue acquisition.”
Peritoneal mesothelioma, the second rarest form of mesothelioma, is a type of cancer that affects the peritoneum, the thin layer of cells that surrounds the abdominal cavity and allows proper contraction and expansion of organs and structures there. According to the Mesothelioma Cancer Alliance, peritoneal mesothelioma accounts for about 20% of all diagnosed mesothelioma cases. Its diagnosis is somewhat difficult, due to lack of sensitivity in cytological evaluation and difficulty in performing differential diagnosis in relation to other cancers. Usually, it is necessary to perform an invasive laparotomy biopsy or laparoscopic examination to obtain a definitive diagnosis.
Diagnosis through EUS-FNA, useful in malignant lymphoma, pancreatic tumor, and gastroduodenal submucosal tumor, is very rare in the cases of peritoneal mesothelioma, though it has been reported for diagnosis of pleural mesothelioma.
In this study, researchers describe the case of a 73-year-old man, with a history of colon cancer, that presented an abdominal mass. Several diagnostic procedures were applied, such as computed tomography (CT), fluorodeoxyglucose-positron emission tomography (FDG-PET), and EUS-guided tissue acquisition using EUS-guided through-the-needle biopsy (EUS-TTNB) and fine-needle aspiration. These procedures revealed a mass in the duodenum and a mass infiltrating both the liver and duodenum. Immunohistochemical staining finally confirmed a diagnosis of recurrent malignant mesothelioma.
The researchers conclude in their final remarks, “We reported a case of peritoneal mesothelioma successfully diagnosed by EUS-guided tissue acquisition. EUS-guided tissue acquisition should be the first diagnostic procedure, rather than invasive procedures such as laparoscopy and/or laparotomy.”