The role of diagnostic procedures is invaluable in situations where a confident diagnosis cannot be made based on less invasive methods (mainly radiological). During a diagnostic procedure, material is taken from macroscopically cancerous tissue for microscopic examination. This is then sent to the pathomorphology laboratory for histopathological evaluation, to confirm or exclude the diagnosis of a primary malignant tumour or its recurrence. The surgeon during surgery may sometimes also examine other systems and organs (e.g. during abdominal exploratory surgery) and assess the stage of the disease for the implementation of the most effective treatment.