Immunohistological determination of proliferative activity in seminomas.

The proliferative activity and growth pattern of 20 seminomas were determined immunohistologically with the monoclonal antibody Ki-67. A growth fraction of tumour cells between 50 and 80% was found in seminomas with an almost even distribution of proliferating cells in all sections, regardless of tumour size. There was a slight tendency towards a greater growth fraction in tumours at an advanced histopathological stage. No positive correlation could be found between growth fraction and tumour size or lymphocytic infiltration. The results confirm the well known sensitivity of seminomas to radiation and chemotherapy and show that the determination of proliferative activity should be included in the histopathological routine diagnosis of malignant tumours with regard to systemic treatment and prognosis.