<aside> 💡 CD5+, CD23+, CD19+, CD200+, LEF1+, CD20-dim, sIg-dim, CD43+/-, CD10-, CD79b−, cyclin D1-, SOX11- and FMC7−

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Epidemiology

• It is the most common form of leukaemia within Europe and the USA but less frequent elsewhere.
• Median age: 70, M:F = 2:1.

Clinical Manifestations

• CLL/SLL usually presents in elderly patients with a leukemic phase, generalized lymphadenopathy and often hepatosplenomegaly on routine physical examination. Bone marrow involvement is often extensive.
• Immunosuppression is often a significant problem resulting from hypogammaglobulinaemia and cellular immune dysfunction.
  • Hypogammaglobulinemia becomes more frequent and marked as the disease progresses.
  • Apart from hypogammaglobulinemia, there are alterations in T-cell function, abnormalities in complement activation and dysfunction in the neutrophils/NK cells/monocytes.
  • Pure red cell aplasia can sometimes be observed with isolated anemia and absence of RBC precursor cells.
• Lymphocytosis. The absolute clonal B cell lymphocyte count is >5000/μL and may be up to 300000/μL or more. Small, round lymphocytes with condensed chromatin and scant cytoplasm. These cells often show multiple chromatin condensations in a “soccer ball” pattern.
• Normochromic normocytic anemia is present in later stages as a result of marrow infiltration or hypersplenism. Anemia usually precedes thrombocytopenia when cytopenia is caused by marrow replacement.
• Autoimmune hemolysis may also occur in approximately 10% to 25% of CLL patients at some time during the course of the disease.
• Immune thrombocytopenia purpura (ITP) occurs in 1% to 2% of patients and may be suspected if there is a sudden isolated fall in platelets in the absence of splenomegaly.
• A number of other conditions may be caused by antibodies produced directly by the CLL cells and these include cold agglutinin disease, peripheral neuropathy, and paraneoplastic pemphigus.
• Bone marrow aspiration shows up to 95% lymphocytic replacement of normal marrow elements. Trephine biopsy reveals nodular, interstitial or diffuse involvement by lymphocytes, with the latter having a worse prognosis. Morphologic features that correlate with a worse prognosis include prominent proliferation centers in lymph nodes or >10% of prolymphocytes (intermediate-size lymphocytes with prominent central nucleoli) in the blood.
• Hypercalcemia and markedly elevated lactate dehydrogenase (LDH) are not common in CLL and suggest Richter transformation.
• Up to 10% of CLL patients have a first-or second-degree relative with CLL, making CLL one of the most common types of malignancy with familial predisposition. Patients with such a family history are generally diagnosed a median of 10 years earlier than other patients.

Diagnosis

Immunopheontype