Role of Preoperative Sonography in the Diagnosis and Pathologic Staging of Pseudomyxoma Peritonei

Objectives The purpose of this study was to analyze the sonographic features of pseudomyxoma peritonei and the ability of preoperative sonography to assess the pathologic grades of this disease. Methods Nineteen patients with pseudomyxoma peritonei who underwent preoperative sonographic examinations were included (9 male and 10 female; age range, 31–70 years). Four patients presented with disseminated peritoneal adenomucinosis, 7 with peritoneal mucinous carcinomatosis with intermediate or discordant features (intermediate‐grade disease), and 8 with peritoneal mucinous carcinomatosis. The sonographic characteristics, clinical features, and serum tumor marker levels were recorded and compared among the 3 grades. Results Clinical symptoms and carcinoembryonic antigen, cancer antigen 125 (CA‐125), CA‐19‐9, CA‐724, and CA‐153 levels were not significantly different among the 3 pathologic grades ( P > .05). Ascites, scalloping of the visceral margin, invasive parenchymal nodules, and peritoneal masses were detected in all grades. Disseminated peritoneal adenomucinosis occurred without the finding of an omental cake. The presence of enlarged lymph nodes was more common in peritoneal mucinous carcinomatosis. The diagnosis of pseudomyxoma peritonei was made by preoperative sonography in 1 case. Four cases were diagnosed as ovarian mucinous cystadenoma with rupture. One case was diagnosed as a mucinous appendiceal cyst. Four cases were diagnosed as ascites or encapsulated effusion. One case was misdiagnosed as lymphoma. The others were diagnosed as celiac masses. Conclusions Preoperative sonography can be used to diagnose pseudomyxoma peritonei as long as radiologists are familiar with the imaging features. Although there are overlaps in the sonographic findings among the different grades, some features may aid in separating them.