Tropical Granulomas: Diagnosis

Abstract

A granuloma is a focal collection of inflammatory cells that include mononuclear cells, macrophages, and giant cells along with a number of lymphocytes, plasma cells, and fibroblasts. Granulomatous reactions may be classified functionally into two major categories (1). The first group consists of lesions characterized by delayed-type hypersensitivity, antigen- specific response. These granulomas have a high rate of cell turnover, are very active lesions, and are seen in tuberculosis, sarcoidosis, hypersensitivity pneumonitis, and schistosomiasis. The second type is a foreign body granuloma that lacks an antigen-specific response and often is an inactive, minimally destructive lesion. These low-turnover granulomas are seen in berylliosis, where the offending agent is inanimate and inert. The composition of the causative irritant and its degradability and immunogenecity are decisive factors in the development of a granuloma (2). © 2006 by Taylor and Francis Group, LLC.