Extramedullary chronic lymphocytic leukemia: systematic analysis of cases reported between 1975 and 2012.

The prognostic significance of extra-medullary chronic lymphocytic leukemia (EM-CLL) is unknown. We conducted a Medline database systematic search analyzing English language articles published between 1975 and 2012 identifying 192 cases. Patients with EM-CLL were more commonly treated than not (p < .001). Skin and central nervous system (CNS) were the most commonly reported sites of organ involvement. Survival after diagnosis of EM-CLL appeared to depend on the site of EM involvement. Prospective evaluation and further studies of EM-CLL are warranted.