Pseudomyxoma peritonei is rare tumor that presents insidious evolution and is characterized by mucinous ascites or implants in the peritoneal cavity. The origin of this tumor is frequently the appendix or the ovaries. Diagnosis can be established by fine needle aspiration cytology, ultrasonography, computed tomography or magnetic resonance imaging . The authors report three cases of patients with pseudomyxoma peritonei arising from the ovary that were submitted to computed tomography and magnetic resonance imaging examinations of the abdomen. This paper emphasizes the importance of these imaging methods that permit greater spatial resolution, multiplanar images and different types of sequences (magnetic resonance imaging), and allow better evaluation of these lesions. Computed tomography examinations showed lobulated low-density masses with well defined limits causing "scalloping" of the hepatic and splenic borders due to extrinsic compression by adjacent peritoneal implants. Invasion of the liver and spleen was not observed. Magnetic resonance imaging examinations revealed expansive peritoneal lesions with low-intensity signal on T1-weighted images and high-intensity signal on T2-weighted images, adjacent to the hepatic and splenic borders.

Keywords: Pseudomyxoma peritonei. Computed tomography. Magnetic resonance imaging.

Closed loop obstruction of the bowel is an extremely grave condition that may lead to serious consequences and even be fatal. The authors describe a case of a patient with intestinal obstruction secondary to cancer of the sigmoid and highlight the importance of computed tomography in the analysis of the pathological changes in routine management of patients with acute abdomen.

Keywords: Computed tomography. Small bowel obstruction. Rupture of the cecum. Cancer of the sigmoid.