Cellular cannibalism in central and peripheral giant cell granuloma of the oral cavity can predict biological behavior of the lesion

Abstract

Cancer cannibalism is used to differentiate benign tumors from malignant, but recently the phenomenon has been demonstrated in giant cell tumor of tendon sheath (localized type). Microscopically and pathogenetically, this tumor is similar to central giant cell granuloma (CGCG) and peripheral giant cell granuloma (PGCG) of oral cavity. Hence, attempt has been made to study the cannibalistic giant cells (GCs) in CGCG and PGCG with their correlation with the biological behavior. Surgically treated 16 CGCG and 23 PGCG cases with adequate clinical and radiographic documentation were selected. Quantification of cannibalistic GCs was performed using routine HE stain. Hundred GCs were examined in each section, and number of cannibalistic cells was expressed in percentage. Ten cases were randomly selected for further immunohistochemical analysis with CD68 and bcl-2. Cannibalism was found in all the cases (100%). The frequency of occurrence of cannibalistic GCs ranged from 20% to 56% with a mean of 33.62 ± 8.9. CGCG showed significantly higher mean cannibalistic GC frequency (38.06 ± 10.15) than PGCG (30.04 ± 5.63). In aggressive CGCG, mean cannibalistic GC frequency was significantly higher (42.20 ± 10.4) than non-aggressive type (31.17 ± 6.014). Similarly, recurrent cases showed significantly higher mean cannibalistic cell frequency (43 ± 6.26) than non-recurrent cases (30.81 ± 6.66). Immunohistochemistry results showed histiocytic nature of GCs as well as mononuclear cells. The internalized cells did not expressed bcl-2, suggesting that the internalization induces apoptotic cell death. Assessment of frequency of cannibalistic cells in CGCG and PCGC could help in predicting the biological behavior of the tumor.