The anatomy of the P lymphocyte.

This paper describes the basic morphologic criteria for identifying the P lymphocyte. The P cell is a stimulated atypical lymphocyte that is found in schizophrenics and some of their relatives. This cell is suggested as a tentative laboratory indicator of the schizophrenia process. The main identifying features of the cell are its high cytoplasmic basophilia and leptochromatic nuclear structure. Furthermore, the cytoplasm often contains vacuoles and the nuclear shape is often irregular with one or more nucleoli visible. Color micrographs are used to illustrate the cell features.