Occurrence of multinucleated giant cells in the appendix of clinically healthy rabbits

The spontaneous formation of multinucleated giant cells was observed in the appendix of clinically healthy adult rabbits that were free of infection with intestinal viruses, pathogenic bacteria, fungi and parasites. Giant cells occurred singly and in aggregates. They were of the foreign body and of the Langhans' type, but intermediate forms were also noticed. Ultrastructurally, the hallmark of these appendiceal polykaryons were large phagolysomal fields harbouring amorphous debris and remains of cytoplasmic organelles and bacteria. The bacteria in the appendiceal tissues were neither of a special type nor acid-fast. The aetiology and significance of appendiceal giant cells remains to be clarified.