Diffuse decidual leucocytoclastic necrosis and NK cell aggregates: two distinct features of miscarriage

Aims Primary histopathology of miscarriage remains undetermined in the majority of cases. This study was conducted to determine histological characteristics pertinent to miscarriage. Methods The study groups were composed of elective abortions (n=29) and miscarriages (n=45) comprised of chromosomally normal (n=15) and abnormal cases (n=30). Immunohistochemistry was done against CD3, CD8, TIA-1 and CD56. Results Two histological features—diffuse decidual leucocytoclastic necrosis (DDLN) and decidual natural killer cell aggregates (NKCA)—were relatively common in miscarriages. The frequencies of DDLN and NKCA were different between the groups (p Conclusions The findings strongly suggest that defective placentation and abnormal maternal immune response are associated with miscarriage. DDLN and NKCA seem to have diagnostic values in the pathological evaluation of miscarriage.