Isolated massive histiocytes renal interstitial infiltration: a case report of an unexpected cause of acute kidney injury in a kidney transplant recipient.

Renal histiocyte activation and infiltration may have been initiated by an immunological mechanism similar to what occurs in HLH and infectious processes. The present case highlights the occurrence of isolated massive renal interstitial infiltration of histiocytes that does not meet the criteria for HLH or other related pathologies.