[External quality control of immunohistochemical studies in pathomorphology: tasks, problems, solutions, development prospects].

In 2022, the Quality Control Center for Immunohistochemical Studies of the Russian Medical Academy of Continuing Professional Education conducted 12 rounds of markers for breast, lung, prostate, bladder cancer with the participation of 83 laboratories. For the first time, a round was held to control the method of in situ hybridization in the diagnosis of breast cancer, and a digital round. Typical problems in carrying out immunohistochemical studies in oncomorphology have been identified and the importance of participation of laboratories in external control has been shown.