Presentation: usually middle age (50's) but may present from 20 to 90
Common symptoms:
(1) fatigue
(2) signs of splenic infarction and/or rupture (abdominal pain, intra-abdominal hemorrhage)
(3) recurrent infections
(4) bleeding or easy bruisability
Common clinical findings:
(1) splenomegaly
(2) occasional hepatomegaly
(3) vasculitis and/or polyarthritis (autoimmune disorder)
Less frequent findings:
(1) ascites
(2) lymphadenopathy (usually absent)
(3) meningitis
Laboratory findings:
(1) anemia, thrombocytopenia and/or absolute neutropenia; pancytopenia
(2) monocytopenia in untreated patient
(3) atypical lymphocytosis with cytoplasmic projections ("hairs") and lacy nuclear chromatin
(4) bone marrow infiltrate with increased reticulin, which can result in a dry tap if diffuse
Diagnostic laboratory findings:
(1) strong cytoplasmic staining for tartrate resistant acid phosphatase (TRAP) in the atypical lymphocytes
(2) flow cytometry is:
(2a) positive for CD20, CD22, FMC7 and CD79a
(2b) negative for CD5, CD10, CD23 and CD79b
(2c) positive for CD11c and CD103; CD25 (interleukin-2 receptor alpha subunit) usually present
