1. Presence of plasma cells in the circulating blood.

2. Presence of unusually large proportions of plasma cells in the tissues or exudates.

Origin

[plasmacyte + G. -osis, condition]

Stedman's Electronic Medical Dictionary, 1996

Plasmacytosis means the presence of plasma cells in the organs that usually we can not find plasma cells in them, for example blood or bone marrow. Plasma cells are seen in the blood stream of the patients whi have multiple myeloma, some of the viral or bacterial infectiona as IMN and in some of the allergic reactions. The presence of plasma cells in the bone marrow biopsy of a male or female over 50 is a good reason to make the diagnosis of multiple myeloma ( which is a kind of malignancy) for him or her.