Sandbox leucocytosis

• Leukocytosis is defined as an elevated white blood cell (WBC) count greater than 11,000 per mm3 (11.0 × 109 per L).
• The most common type of leukocytosis is neutrophilia.
  • Neutrophilia can be defined as an increase in the absolute number of mature neutrophils to greater than 7,000 per mm3 [7.0 × 109 per L].

			Differentiating Symptoms	Differentiating physical exam findings	Differentiating Labs
Physiological variation	Birth
	Adult
	Pregnancy
Primary	Congenital	Heridatary neutrophilia
		Chronic idiopathic neutrophilia
		Down syndrome
		LAD
	Acquired	CML
		Polycythemia Vera
Secondary	Infection	Acute
		Chronic
	Connective tissue disorders	RA
		JRA
		IBD
		Chronic hepatitis
	Drug induced	Steriod
		Lithium
		Beta agonists
		Cytokines
	Marrow stimulation	Hemolytic anemia
		Immature thrombocytopenia
	Post splenectomy
	Metabolic	Diabetic coma
		Acidosis
		Thyroid strom
		Acute Gout
		Seizures

Differential diagnosis of Lymphocytosis

	Pathophysiology	Symptoms	History	Physical Examination	Laboratory Findings
					CBC	Blood smear	Immunophenotype
Monoclonal B lymphocytosis	Monoclonal population of B lymphocytes <5000 cells/microL	Without other features of Lymphadenopathy Organomegaly Cytopenias Extra-medullary involvement	Active or prior infections History of hematologic malignancy Medications Family history of chronic lymphocytic leukemia (CLL)	Fever Lymphadenopathy Hepatosplenomegaly Joint redness Abdominal pain Lung findings.	Lymphocytosis ≥4000 lymphocytes/microL	Lymphocytes in MBL have no distinguishing appearance Appear as small, mature mononuclear cells.	CD19, CD20, and CD23	Does not require bone marrow examination or imaging for diagnosis
Congenital B cell lymphocytosis
Large granular lymphocyte leukemia							CD3, CD57, CD56 CD3-, CD56+
Chronic lymphocytic leukemia
Sezary syndrome
Mantle cell lymphoma
Follicular lymphoma
Splenic marginal zone lymphoma
Acute lymphoblastic leukemia
Acute Promyelocytic Leukemia
Diffuse Large Cell Lymphoma