Modern pathology supports clinical medicine in the prevention, diagnosis and treatment of many diseases, particularly cancer.

A major focus lies on microscopic diagnosis of tissue samples, body fluids and swabs taken from physicians of many disciplines, such as surgeons, gynaecologists, urologists, dermatologists and internists as part of their clinical examination.

The histological examination of tissue samples often provides crucial evidence about the correct diagnosis. Thus, a positive diagnosis of tumour type and the assessment of its virulence (aggressivity) may ultimately be made only by microscopic examination and results in clear therapy concepts.

Successful therapy in oncology depends on accurate diagnosis of the tumour and can be decisive for the type of treatment. A thorough pathological examination according to the latest findings which includes conventional light microscopic examination (histology), but nowadays also standard immunohistochemical studies and in some tumours also the determination of molecular and genetic characteristics (sequence analysis of genes), is often crucial for decision making of further treatment (e.g. radiation, chemotherapy, immuno-therapy, hyperthermia, vaccination, etc.).

In preventive medicine smear sample of various organs, e.g. in gynaecology, are important. They are not invasive and help to identify early forms of tumours. Treatment of early stage cancer has in general a good prognosis.