The history of calculus mendax and the following surgery on the prostate.

In this paper we would like to present probably the first surgery performed on the prostate gland followed by microscopic analysis of the obtained tumor tissue sample. We based on the existing correspondence between Ludwig von Hammen and Johann N. Pechlin, and their successors in this field as well. Von Hammen seems to be a pioneer in the area of not only urological surgery but in directing this part of medical practice from "lithotomists" to physicians, much better educated than barbers in physiology but first of all in anatomy. This 17th century physician from Gdansk tried to set new standards both for surgical medical practice but histopathological examination of the excised material as well. Due to the change of the operational skills and procedures von Hammen's work got almost forgotten, but remains remembered due to the work of historians of the medicine from following centuries.