Residual abdominal masses after chemotherapy for nonseminomatous testicular cancer: correlation of CT and histology.

Computed tomographic (CT) characteristics of 45 residual masses in 30 patients with disseminated nonseminomatous testicular cancer treated with chemotherapy were correlated with histologic findings at surgery. Thirty-one masses were studied serially on pre- and postchemotherapy scans. At the time of tumor-reductive surgery, all patients had normal serum tumor markers (alpha-fetoprotein and human chorionic gonadotropin). Residual malignancy was found in 27% of patients, teratoma in 33%, and fibrosis or necrosis in 40%. The CT appearance of the masses--size, qualitative density, and change noted during the course of treatment--was insufficient to exclude the presence of residual malignancy or teratoma. An enlarging mass of psoas density occurred only once in this series; it contained malignancy. Other CT characteristics of residual masses had no greater than 50% correlation with the presence of malignancy. Histologic evaluation of residual masses remains necessary to guide further patient management.