Mononuclear cell phagocytosis in giant cell lesions of the jaws

The central giant cell lesion (CGCL) is a benign intraosseous lesion that may resemble other giant cell-rich lesions, such as the peripheral giant cell lesion (PGCL). This lesion may be classified as aggressive or non-aggressive according to clinical and radiographic criteria, however, there is no biological marker that may help to define the CGCL based on the biological behavior. In this context, stromal cell phagocytosis has been described as an event related to aggressive lesions, however, only a few studies have investigated this phenomenon in CGCL. The aim of this study was to compare mononuclear cell phagocytosis by the multinucleated giant cells between aggressive, non-aggressive CGCL and PGCL.

Thirty-three cases of CGCL, 10 aggressive and 23 non-aggressive, and 20 cases of PGCL were included in this study. Phagocytosis events were evaluated in five consecutive microscopic fields from histological sections, stained with hematoxylin and eosin. The ratio between the numbers of phagocytosis/mm²and the total number of multinucleated giant cells/mm²was calculated.

Phagocytosis was observed in the multinucleated giant cells of all cases. The density of phagocytosis/mm²in relation to giant cells/mm²was higher in the CGCL than in the PGCL. In addition, aggressive CGCL showed higher phagocytosis events when compared to the non-aggressive variant.

Our results suggest that the aggressiveness of multinucleated giant cell lesions of the jaws may be related to the number of phagocytosis events in the lesion.