Giant cells resembling those found in tuberculous nodes appeared in cultures of various normal and pathological human lymph nodes cultivated in plasma. They migrated out from the explants from normal and tuberculous nodes, from nodes from acute and chronic lymphadenitis and Hodgkin's disease, and from a metastatic sarcoma. They were most abundant in cultures from tuberculous nodes. The giant cells are similar in structure to the large wandering cells and probably arise from them. We are uncertain, however, as to how the giant cells develop. There is no evidence of fusion of the large mononuclear wandering cells; on the other hand, there is some evidence that they arise by amitosis of the nuclei without division of the cytoplasm, which increases in bulk.
They contain a large central area of more or less granular character which takes up neutral red with great avidity. This central area probably consists of dead material, the waste products of metabolism and of digested foodstuffs such as lymphocytes that the cells are unable to get rid of in the abnormal environment, and perhaps also of accumulated non-living foreign substances that have penetrated into the cells and become segregated.
The central area is surrounded by a conspicuous zone of fat globules in which the nuclei are embedded.
The nuclei vary in number from 2 or 3 to 50 or 60. Usually, however, there are not more than 10 or 20, and in the cells that are flattened out on the cover-slip they often have a horseshoe-like arrangement about the equator of the central area.
Mitochondria are abundant and usually in the form of wavy or curly threads. They seem to be most numerous in the ectoplasm immediately about the fat zone. They also extend in among the fat globules and out into the ectoplasm.
A distinct, clear, homogeneous ectoplasm envelops the cell.