Lymphoid proliferations of indeterminate malignant potential arising in adults with common variable immunodeficiency disorders: unusual case studies and immunohistological review in the light of possible causative events.

Patients with common variable immunodeficiency disorders (CVIDs) who developed B cell lymphoproliferation of indeterminate malignant potential are described in order to raise a discussion of the relationship between infection and lymphoproliferation in infection prone patients. Those with CVID are at risk of developing either polyclonal or monoclonal lymphoproliferation in part due to the dysregulation of their adaptive immune systems. The aetiologies of the lymphoproliferations are unknown but intriguing; the relevance of infection being particularly problematic. The patients described here demonstrate variability in preceding infection, age at presentation, response to antibiotics and other types of therapy as well as outcome. The question of treatment is also controversial; issues include whether antibiotics or chemotherapy are the first line of therapy in all patients and whether transformation to aggressive B cell malignancy is inevitable or depends on other factors and if so, the length of time for such progression.