Definition
Lymphocyte count on FBC in an adult patient that is greater than the upper limit of the normal range: please only refer if above 10 x 109/l, unless the patient has other symptoms in which case the threshold is lower (see below).
Lymphocytosis is common and is usually a reactive response that does not require any intervention. It occurs in viral infections, autoimmune disorders including connective tissue disorders, thyroiditis, diabetes etc. It is frequent in smokers and post splenectomy.
C.M & L.W 24-7-26
Who to refer:
Please refer:
- Symptomatic patients (significant unintentional weight loss, fever, new persistent drenching night sweats) with a lymphocyte count >5 x 109/l
- Patients with lymphadenopathy (nodes >1 cm) and/or splenomegaly and/or cytopenias (Hb <100, neutrophils <1.0, platelets <100) with a lymphocyte count >5 x 109/l
- Patients with a lymphocyte count >10 x 109/l for >3 months on repeat testing.
Please refer URGENTLY:
- symptomatic patients or if there is presence of lymphadenopathy or splenomegaly.
Who not to refer:
- Asymptomatic patients with a single lymphocyte count >10 x 109/l. Instead repeat FBC in 3 months.
- Asymptomatic patients with a lymphocyte count of 5-10 x 109/l. Instead repeat FBC in 6 months and if minimal change repeat FBC annually thereafter.
How to refer:
SCI Gateway to the Department of Haematology WGH or SJH.
- FBC
- Blood film.
- LFTs.
- Viral serology for EBV (IgM), CMV (IgM), HIV & Hepatitis viruses (HepBs Ag, HepB core Ab, HepC Ab)
The significance of lymphocytosis in routine clinical practice: data from the South East Scotland Cancer Network
Gabrielle E. Clark, Christopher Mullen, Laura E. McGlinchey, Victoria Campbell.
