Intercellular junction formation between polymorphonuclear leukocytes, and between polymorphonuclear leukocytes and tumor cells.

Morphologic evidence of intercellular junctions was found between polymorphonuclear leukocytes (PMNs) and between PMNs and tumor cells. All these junctions displayed electron-dense plaques along the plasma membranes with linear spaces in between. These plaques were finely granular and devoid of filaments. Fine granules were also observed in some of these linear spaces. The significance of these morphologic findings is not known but may be elucidated by a correlative type of study.