Diagnostic value of computed tomography and magnetic resonance imaging in ovarian malignant mesothelioma.

OBJECTIVE: To investigate the diagnostic value of computed tomography (CT) and magnetic resonance imaging (MRI) in ovarian malignant mesothelioma (OMM). METHODS: The clinical and imaging data of 10 pathologically-confirmed OMM patients were analyzed retrospectively. RESULT: (1) The patients were 27 years to 70 years old, with an average age of 57.2 ± 15.4 years. Seven patients reported abdominal distension and pain, 1 reported lower abdominal discomfort and decreased appetite, and 2 patients had no symptoms. (2) Two cases of localized OMM with incomplete semi-annular "capsule" observed around the localized OMM tumors were reported while 8 cases had diffuse OMM in which the tumor parenchyma showed isointense or slightly hypointense on T1WI, inhomogeneous hyperintense on T2WI, and obviously hyperintense on DWI, with obvious inhomogeneous enhancement after enhancement. Diffuse OMM was not mainly composed of ovarian masses and was mainly characterized by mild ovarian enlargement, nodular and irregular thickening of the peritoneum, cloudy omentum, unclear fat gap, and reticular or irregular thickening, which can fuse into a "cake-shape". (3) All 10 patients underwent surgery, while 9 patients underwent systemic chemotherapy or immunotherapy after surgery. All patients with localized OMM survived. Out of the 8 diffuse-type patients, 5 died, 1 was lost to follow-up, and 2 survived. CONCLUSION: OMM has certain clinical and imaging characteristics. There is no liquefaction, calcification, or partition in the tumor. The ovarian enlargement in the diffuse lesion is not significant. The diffuse thickening of the peritoneum and omentum with early appearance of mural nodules and ascites in the upper abdomen, help the diagnosis of OMM.

[CT and MRI manifestations of the axial area primary peripheral primitive neuroectodermal tumors].

OBJECTIVE: To explore CT and MRI manifestations of the axial area peripheral primitive neuroectodermal tumors (pPNETs) in order to improve the knowledge of this disease. METHODS: The clinical data of 10 patients with pPNETs underwent pathologically confirmed were retrospectively analyzed from October 2008 to May 2014. There were 7 males and 3 females, aged from 8 to 49 years old with median of 23.6 years. The preoperative multi-slice spiral CT scan was completed in 3 cases, plain CT scan and enhancement in 4 cases; MRI and enhancement scanning in 5 cases; and among them, 2 cases underwent both MRI and CT scan. RESULTS: In-bone type was found 6 cases and out-bone type was found 4 cases. Three cases occurred in sacral vertebrae, 2 cases in lumbar vertebrae, 1 case in cervical vertebrae, 1 case in cervical spinal canal, 1 case in coccyx, 1 case in the right iliac bone, 1 case in presacral space. Cross sectional the smallest tumor maximum level was 1.1 cmx 1.2 cm in size, the biggest tumor was 8.0 cm x 9.2 cm, the median size was 4.4 cm x 5.7 cm, of them, the tumor of maximal diameter larger than 5 cm had 6 cases. Except 2 cases-without destruction of bone, the other 5 cases with osteolytic destruction, 2 cases with calcification, 1 case with mixed. Equidensite was main in CT scan, 1 case with uniform density, other 6 cases with uneven density,in which 3 cases with "floating ice" change; 1 case with moderate strengthening, other 3 cases with obviously strengthening, 2 cases with multiple small blood vessels in enhancement scanning. MRI of 5 cases showed the signal of isointensity on T1WI, the slightly high signal on T2WI and the signal was not uniform; after enhancement scan, the signal of 5 cases obviously enhanced. Two patients complicated with vertebral compression fractures, no periosteal reaction was found in all patients, and no the destruction of intervertebral disk was found in 5 patients of MRI scan. CONCLUSION: The axial area pPNETs is common among children and the youth, and the mass often is huge. The mass of in-bone type often envelopes the vertebral body, and main located on prevertebral space, all associated with bone destruction, osteolytic destruction is common, and primary vertebral bodies also is common, attachment primary or involvement is few found, it can involve the spinal canal and anterior wall of spinal canal is common, some cases complicate with multiple newly born small vessels. The mass of out-hone type in deep soft tissue is common, minority primary spinal canal, many complicated with vertebral bone destruction, osteolytic destruction was main. The intervertebral disk was not invaded and intervertebral space has not stenosis. CT scan offer complicate with "floating ice" sign, and in-bone type is common. Isointensity is main on MRI TlWI and slightly longer signal is main on MRI T2WI, strengthening signal is obvious.