Hodentumoren

Although they are a rarity with about 1% of all malignant tumors of the adult male, testicular tumors represent a diagnostic challenge for the pathologist due to their morphological diversity. The incidence of germ cell tumors has increased steadily in recent years and they represent the most common malignant tumor in the young man between the ages of 15 and 45. The mortality rate could be reduced dramatically with the introduction of platinum derivatives, so that today over 90% of patients can be cured even in the metastatic state.

Germ cell neoplasia in situ (germ cell neoplasia in situ, GCNIS, Figure 1), in which the tumor cells remain confined to the testicular tubules, is regarded as a reliable precursor lesion. If atypical germ cells break through the testicular tubules and infiltrate the surrounding tissue, invasive germ cell tumors arise. The reason for the development of GCNIS is assumed to be that primordial germ cells / gonocytes do not differentiate into spermatogonia (Figure 2). An important molecular change is the gain of chromosomal "material" on chromosome 12, usually in the form of an isochromesome 12p.

The invasive germ cell tumors are differentiated histologically and clinically into seminomas and non-seminomas. The group of non-seminomas includes embryonic carcinomas, yolk sac tumors, chorionic carcinomas and teratomas. The exact distinction of the histological types is of great importance for the further therapeutic procedure. We can use molecular changes (such as the appearance of an isochromome 12p, Figure 3) to prove the "germ cell tumor origin" in difficult cases and thus form the basis for further therapy for the clinical colleagues.

TGCT therapy consists of inguinal testicular removal and, depending on the clinical stage, subsequent chemotherapy. The mortality of the TGCT could be reduced significantly with the introduction of platinum derivatives. Even with metastatic TGCT, 80% of patients can be cured with cisplatin-based polychemotherapy. In contrast, cisplatin-resistant patients have a very poor prognosis. New therapeutic options for these patients are rare and only a few therapeutic agents have been found in the past decades.

The aim of our working group is to typify the different testicular tumors as best as possible, to detect possible resistance mechanisms in TGCT and to identify potential therapeutic starting points in refractory germ cell tumors.