Tenascin in reactive lymph nodes and in malignant lymphomas.

Tenascin is an extracellular matrix protein which accumulates in the stroma of various malignant and some benign neoplasms. This has been verified in several immunohistochemical studies. The distribution of tenascin immunoreactivity in lymphatic tissues and neoplasias, however, has not been thoroughly studied. In this investigation we analyzed tenascin immunoreactivity in several benign and malignant lymphatic lesions, including both Hodgkin's and non-Hodgkin's lymphomas. In benign lymph nodes, faint reticular immunoreactivity could be observed in the lymphatic tissue. In benign reactive hyperplasias, a stronger reticular pattern of tenascin immunoreactivity was observed in the interfollicular and medullary areas, while the lymphoid follicles contained only a few positive fibers. A similar immunoreactivity was observed in malignant follicular lymphomas. In diffuse lymphomas, a diffuse meshwork of positively stained fibers was seen. This was also the case for the three cases of Hodgkin's disease of the lymphocyte-predominance nodular subtype. There was no difference in the intensity of the immunoreactivity between benign and malignant disorders. However, in Hodgkin's disease of the nodular sclerosis and lymphocyte-depletion subtypes, a much more pronounced immunoreactivity could be observed in the fibrous septa and the cords. This suggests that the tumor cells are possibly capable of synthesizing growth factors which stimulate fibroblasts to synthesize tenascin. The results indicate that tenascin does not accumulate in the stroma of malignant lymphoid neoplasms with the exclusion of some subtypes of Hodgkin's disease. The distribution of tenascin immunoreactivity in lymphatic tissue is similar to that of the reticular fibers suggesting that the molecules are associated with these structures.(ABSTRACT TRUNCATED AT 250 WORDS)