[Demonstration of clusters in nasal polyps a light and electron microscopic investigation (author's transl)]

Numerous functional studies have shown that lymphocytes and macrophages cooperate during the immune response. Cell clusters, consisting mainly of macrophages and lymphoid cells, were found in nasal polyps in humans, especially the oedematous type. Within the clusters the cells showed close physical contact brought about by microvilli of varying length, suggestive of cellular cooperation. These cell clusters resemble the formations found in vitro and in vivo during immunization procedures.