Langhans' giant cells and tubercle bacilli in 91 pulmonary tuberculous lesions resected after prolonged combined chemotherapy.

The Langhans’ giant cell described in 1868 is a large cell with numerous nuclei arranged in a ring around the periphery of an eosinophilic cytoplasm.1’ 2 The cytoplasm is homogeneous or granular and may contain inclusions such as Mycobacterium tuberculosis. The foreign body type giant cell can be distinguished by the presence of nuclei throughout the substance of the cytoplasm rather than at the periphery. Both cell types are found in the granuloma of tuberculosis as well as the granulomata of sarcoidosis, berylliosis, leprosy, syphilis, actinomycosis, histoplasmosis, coccidiomycosis, leishmaniasis and lymphogranuloma venereum. Langhans’ giant cells are thought to result from the fusion or incomplete, amitotic division of epithelioid cells (histiocytes) ,2 In clinical tuberculosis the intact M. tuberculosis is thought to be the agent responsible for the formation of giant cells. Lipid extracts (phospholipids) of the tubercle bacillus may cause a giant cell reaction but only with relatively large doses. Numerous other studies have attempted to determine the relative importance of the tubercle bacillus and the host factors in the giant cell reaction. Several recent studies37’ ‘‘ have indicated that tubercle bacilli in caseous pulmonary tuberculous lesions gradually lose their ability to multiply. This happens with or without the influence of chemotherapy. Careful bacteriologic and histologic studies of 130 consecutive pulmonary tuberculous lesions resected after prolonged combined chemotherapy showed a high correlation between bacterial viability and histologic evidences of “activity,” including epithelioid cells, lymphocytes, recent caseation necrosis, giant cells and minimal fibrous reaction.’ The correlation was particularly high for the 94 lesions without an open cavity. The present study covers but one facet of the problem. It is an attempt to correlate the relative number of giant cells in small localized tuberculous pulmonary nodules with the results of bacteriologic analysis.