Periapical Granuloma

The cells of periapical granuloma which are predominantly lymphocytes increase by division at the periphery. 

There are hyperaemia and oedema of the PDL; localised increase in the vascularity leads to local bone resorption mediated by osteoclast mediated delayed hypersensitivity. In the specimen slide, cholesterol crystals having needle-like appearance, and eosinic hyaline bodies known as Rushton bodies are seen. Macrophages and multinucleated giant cells are also seen. Epithelium is present.

The cells in the centre are separated from their source of nutrition; hence degenerate and liquefy. This results in an epithelium lined cavity filled with fluid known as periapical cyst.

Treatment involves RCT with apicoectomy or extraction with curettage.