Amebic granuloma--an experimental study.

The etiopathogenesis of granuloma formation in amebiasis is not known. An experimental study was carried out in 48 guinea pigs arranged into four groups, to assess the role of hypersensitivity in formation of amebic granuloma. Repeated intracecal inoculations of saline in Group I and mixed amebic and bacterial suspension in other groups were made. Animals in Group III were sensitized by amebic antigen and in Group IV by bacterial antigen before inoculations. Lesions produced in the amebic hypersensitive group of animals were notably different from those in other groups. A higher frequency of cecal ulceration and a significantly severe grade of cecal damage was seen in these animals. Extensive pericecal adhesions and marked thickening of the wall produced nodular lesions. Granulomas were formed with dense chronic inflammatory cell infiltration including fibroblasts.