MATURE METASTASIS OF A MATURE TESTICULAR TERATOMA AS DIFFERENTIAL-DIAGNOSIS OF A RENAL ADRENAL TUMOR/

We report on the eighth known case of a mature metastasis of a mature teratoma of the testis. In a 19-year-old patient who had undergone a p yeloplasty of the left renal pelvis 6 years before, a mature metastasi s of an occult mature teratoma of the testis was found at the former o peration sire. This case - in addition to those published previously e mphasizes the fact that a mature teratoma of the testis has to be rega rded as a malignant tumor in adults. It is supposed that the mature te ratoma originates, as other testicular tumors, from carcinoma-in-situ- cells, which are responsible for metastasize and are not detected afte r lysis.