The pathogenesis of oral pulse granuloma: an animal model

Oral pulse granuloma is one of the terms used to describe oral inflammatory lesions characterized microscopically by the presence of giant cells and hyaline rings. The various names proposed for these lesions reflect the lack of agreement regarding their pathogenesis. One theory advanced claims that the process represents a foreign-body granulomatous reaction to implanted vegetable particles, more specifically those of pulses/legumes. In this study an animal model was developed where homogenized cooked legumes were implanted into the orofacial region of rats. Animals were killed at varying intervals ranging from one day to six months and the tissues associated with the implanted material were removed and processed for light microscopy. The experimentally produced lesions had many features similar to those found in humans, the similarities becoming more pronounced with time. The results indicate that the cellulose moiety of food particles of plant origin accidentally implanted into human tissues may cause the granulomatous reaction known as oral pulse granuloma.