[Pituitary necrosis. Decreasing incidence due to modern intensive therapy?]

Pituitary necroses develop from the interruption of circulation in the pituitary stalk, especially due to shock, trauma, etc. We studied the incidence, extent, and outcome of necroses in postmortem series from 1991 to 1998 and compared these with the findings in our own study in the 1970s. Necroses were classified into four degrees based on the proportion of anterior pituitary volume: grade I, up to 5%; grade II, 5-10%; grade III, 10-50%; grade IV, more than 50%. The data show a decreased incidence of necrosis, from 7.7% in the 1970s to 3.1% in the 1990s. Scars, indicating former necroses, decreased in incidence from 11.4% to 3.6%. The changes in the four grades of necrosis were: a decrease in grade I from 60% to 41%, a decrease in grade II from 24% to 22%, an increase in grade III from 9% to 17%, and an increase in IV from 8% to 20%. These figures reveal that pituitary necroses became less frequent but more extensive. Necroses of grade IV are generally caused by more than a single cause. The decreased incidence appears to be the consequence of progress in intensive care over the past 20 years, as patients can now survive severe shock longer. The increased frequency of intensive necroses is probably due to the longer period for greater extent of necrosis to develop during intensive care.