1. The spleen is an organ of multiple structures and many functions, but in the interests of human health and disease, it is probably far more important pathologically than physiologically.
2. It has been abundantly proved that instability in splenic functional balance toward any one of the essential elements of the blood passing through this organ may be an inherited trait, as in congenital hemolytic icterus. Recognition is now made of a syndrome in which, despite intensive compensatory panmyeloid hyperplasia, indiscriminate elimination of all circulating elements occurs, actually simulating panmyeloid hypoplasia. Splenectomy in such a syndrome is often dramatically curative. "Primary splenic panhematopenia" is suggested as an appropriate descriptive designation.
3. The potentially important role which may be played by the spleen, secondarily involved in a wide variety of syndromes, with the precipitation of varying degrees of peripheral cellular disequilibria, demands careful diagnostic discrimination. A dependable experience in the specific technics by which bone marrow and splenic functions are appraised is essential to sound judgment and clinical acumen.
4. The normal spleen is apparently not essential to life and health at any age and, therefore, may be surgically removed without prejudice to future hemolytopoietic equilibria and longevity. The pathologic spleen may at times constitute a very real hazard to health and an actual threat to survival; in the more acute syndromes, prompt surgical intervention may be lifesaving.