ObjectiveTo analyze the CT features of solid pseudopapillary tumor of pancreas (SPTP). MethodsEight patients with SPTP received triple phasic contrast-enhanced CT, and its consistency with pathological findings was analyzed. ResultsSPTP manifested as a solitary and exogenous mass, with a heterogeneous pattern composed of solid and polycystic parts. The shape of SPTP was spherical in four patients, oval in two patients, and shallow lobulation in another two patients. In contrast-enhanced phase images, the solid parts showed mild to moderate enhancement in both arterial and portal phases. Complete capsule was showed in seven patients, and nodules were found in the wall of mass in five patients. Hemorrhage was seen in two patients and calcification was showed in five patients. The dilation of pancreatic duct was found in one patient, liver metastases was showed in one patient, and the invasion of tumor to posterior gastric wall was found in one patient. Pseudopapillary structure, hemorrhage, necrosis, and cystic degeneration were showed in all patients by histological study. ConclusionSPTP has certain characteristic CT imaging manifestations consistent with histological features, which is helpful for the diagnosis and differential diagnosis of SPTP.
ObjectiveTo study the imaging manifestation and clinicopathologic characteristics of rectal stromal tumors. MethodsThe CT and MRI data of 8 patients with pathology proved rectal stromal tumors were retrospectively analyzed, and the correlation between the imaging features and pathological results were analyzed. ResultsAll of 8 cases were malignant. One case was submucosal. It showed irregular thickening of the rectal wall with a diameter of about 2.6 cm, and small ulcers with low-risk could be seen. Three cases were intramural with diameters of about 0.7－10.0 cm. Small lesion located in rectum, and the larger lesions showed internal and external growth across the rectal wall and the main part of the mass was outside the rectum. They were heterogeneous enhancement. One case accompanied with adenocarcinoma. One case was extremely low-risk, two cases were high-risk. Four cases were subserous. The diameter was about 4.2－16.5 cm. CT showed round or lobular, well-circumscribed, exophytic, hypervascular, and heterogeneous masses with cystic necrosis and hemorrhage. They displaced rectum occasionally. Lymphadenopathy in the left groin was developed in one case. Two cases were highrisk, two cases were intermediated-risk. No cases developed intestinal obstruction. Results of immunohistochemistry: CD117 was positive in 7 cases, CD34 positive in five cases, CD117 and CD34 positive in four cases, CD117 negative but CD34 positive in one case, CD117 positive but CD34 negative in three cases. Five cases were followed up, among whom 3 cases recurred. ConclusionsRectal stromal tumor is rare. Imaging appearances of rectal stromal tumors are specific. Its final diagnosis depends on immunohistochemistry examination. It has generally higher degree of malignancy and the prognosis is relatively poor.