Non-cannibalistic tumor cells of oral squamous cell carcinoma can express phagocytic markers.

BACKGROUND: CD68 and lysozyme expression in cannibalistic tumor cells of oral squamous cell carcinoma (OSCC) is well established. Transformation of cancer cells into cannibalistic cells is a process involving sequential events. Initial event could be genetic expression of proteins that is required for execution of cannibalism. Hence, it is quite possible that some non-cannibalistic tumor cells can also show expression of cannibalistic markers (CD68 and lysozyme).

METHODOLOGY: Formalin-fixed tissues of 30 OSCC cases with cellular cannibalism (CC) (positive control), 30 OSCC cases without CC, and 17 normal oral epithelium specimens (negative control) were subjected to immunohistochemical analysis for CD68 and lysozyme expression.

RESULTS: OSCC with CC showed CD68 and lysozyme expression in 30 (100%) cases each {CD68: [weak: 21 (70%), strong: 9 (30%)]; lysozyme: [weak: 24 (80%), strong: 6 (20%)]}. In OSCCs without CC, CD68-positive tumor cells were present in 13 (43.33%) cases [weak: 10 (33.33%); strong: 3 (10%)] and lysozyme expression was present in 13 (43.33%) cases [weak: 12 (40%); strong: 1 (3.33%)]. Control group showed negative expression for CD68 and lysozyme in the oral epithelium. The CD68 and lysozyme expression in OSCCs without CC, OSCCs with CC, and control group showed statistically significant differences (P < 0.001). Significant correlation was also observed between CD68 and lysozyme expression and different grades of OSCC.

CONCLUSION: CD68 and lysozyme expression in non-cannibalistic tumor cells of OSCC can be related to CC.