CT in primary malignant germ cell tumors of the retroperitoneum.

Malignant germ cell tumors may exist as a primary entity in the retroperitoneum. In a CT study of 14 males with this condition (2 seminomas and 12 non-seminomatous tumors) all masses were large, lobulated and of mixed density. Fat plane obliteration against adjacent structures was frequent. The aorta was embedded in 9 patients and the inferior vena cava was affected in 7, 2 of whom had signs of compromised caval blood flow. Distant metastases were found in the lungs (7 patients), liver (n=4), posterior mediastinum (n=3), and in brain and supraclavicular lymph nodes in one patient each. Serum biomarkers were elevated in 11 patients. An extragonadal germ cell tumor should be considered when CT of the abdomen reveals a large retroperitoneal mass with mixed density.     

Cancer of the endometrium: value of MR imaging in determining depth of invasion into the myometrium

The depth of invasion into the myometrium correlates with the frequency of lymph node metastases in patients with cancer of the endometrium. A distinction between superficial invasion (less than 50% of the thickness of the myometrium) and deep invasion (greater than 50%) is particularly important. The ability to distinguish between these two groups on MR was studied in 33 patients with endometrial cancer who had primary hysterectomy. The overall accuracy of MR in showing deep invasion was 82%, with a sensitivity of 91% and a specificity of 64%. The main limitation of MR was four false-positive results with regard to deep invasion. In all of these, the erroneous diagnosis was found at histologic examination to be due to a large polypoid tumor that distended the uterus so that a thin rim of myometrium was stretched over it rather than being deeply infiltrated by it. Our experience shows that MR can be used to distinguish between superficial and deep invasion of the myometrium. However, degree of invasiveness may be overestimated in exophytic polypoid tumors with significant intraluminal extension.     

Clinical stage I carcinoma of the cervix: value of MR imaging in determining degree of invasiveness

The depth of tumor invasion measured at histologic examination is the most important prognostic factor in early-stage carcinoma of the uterine cervix. The ability of MR to estimate the depth of tumor invasion was studied in 47 patients who subsequently underwent radical hysterectomy. In two patients, MR failed to detect tumors with infiltration depths of 2 and 4 mm. The maximum sagittal tumor length along the axis of the cervix (D) and the maximum tumor area on sagittal (S) and axial (A) images were measured with MR. The depth of tumor infiltration determined histologically (I) correlated with the degree of infiltration noted on MR images. The univariate correlation coefficients for log I vs log D, log S, and log A were .87, .84, and .77, respectively. By stepwise inclusion of the variables in a multivariate analysis, the contributions to the coefficient of determination from including log S and log A after log D were less than 1%. The regression analysis showed that the best estimate for the depth of invasion was close to half of the sagittal tumor length measured on MR, I = D/2. Our experience shows that MR is valuable in determining the degree of invasiveness in clinical stage I tumors.     

Computed tomography in primary non-seminomatous germ cell tumors of the mediastinum

Germ cell tumor exists as a primary entity in the anterior mediastinum. In a CT study of two males and one female with primary non-seminomatous germ cell tumors all masses were large and lobulated with a mixed density. The fat planes were for the most part obliterated. A high attenuating border was present around parts of the tumor in all three cases, and the pleura-lung interfaces were irregular. One patient had pericardial and left pleural effusions as well as tumor invasion of the anterior chest wall. An extragonadal germ cell tumor should be considered when CT of the thorax reveals a large mass in the anterior mediastinum of a young adult.     

Magnetic resonance imaging of malignant extradural tumors with acute spinal cord compression

Thirty-six cancer patients with extradural spinal metastatic disease and acute symptoms of spinal cord compression underwent magnetic resonance (MR) imaging at 1.5 T. Cord involvement was found in all 36, 7 of whom had lesions at 2 different sites. Vertebral metastases in addition to those corresponding to the cord compressions were detected in 27 patients, and 18 of these had widespread deposits. MR displayed the extent of the tumors in the craniocaudal and lateral directions. The ability to identify multiple sites of cord and vertebral involvement and to delineate tumor accurately makes MR the examination of choice in cancer patients with suspected spinal cord compression. It obviates the need for myelography and postmyelography CT in this group of patients.     

Osteogenic sarcoma: MR signal abnormalities of the brain in asymptomatic patients treated with high-dose methotrexate

The advent of lesions with high signal intensity in periventricular white matter was incidentally observed on T2-weighted images in one patient who underwent magnetic resonance (MR) imaging of the brain after administration of high-dose methotrexate (HDMTX) for osteogenic sarcoma. Twenty-one additional symptom-free patients who had been treated with the same regimen and 10 patients who had undergone cisplatin-based chemotherapy for testicular cancer also underwent examination. Fourteen of the patients with osteosarcoma showed high-signal-intensity lesions in white matter on T2-weighted images. The interval between the last course of chemotherapy and MR imaging was a factor in this finding, as 12 of 14 patients who underwent examination within 2 years after chemotherapy had a positive finding, as opposed to two of eight patients who underwent examination later. The patients with testicular cancer had normal MR images. The occurrence of MR imaging abnormalities in asymptomatic patients treated with HDMTX for osteogenic sarcoma may be subclinical evidence of treatment-related central nervous system toxicity.