Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma

What is CLL/SLL?

A chronic lymphoproliferative disorder characterized by malignant B lymphocytes in blood, bone marrow, and lymph nodes.

Why are CLL and SLL considered the same disease?

They involve identical malignant cells but differ in presentation (blood vs lymph nodes).

What is the most common hematopoietic malignancy in adults?

CLL/SLL.

What type of cells proliferate in CLL/SLL?

Mature-appearing B lymphocytes.

What is the typical morphology of CLL cells?

Small cells with sparse cytoplasm, round nuclei, and no visible nucleoli.

What are smudge cells?

Crushed fragile lymphocytes seen on peripheral smear.

What is the mnemonic for smudge cells?

Crushed Little Lymphocytes.

Are smudge cells specific for CLL?

No, but they are characteristic and commonly seen.

What is seen on peripheral smear in CLL?

Lymphocytosis with many mature-appearing lymphocytes and smudge cells.

What is seen in bone marrow in CLL?

Normal to increased cellularity with monoclonal B lymphocyte proliferation.

What confirms monoclonality in CLL?

Light chain restriction (κ or λ).

What is seen in lymph nodes in CLL/SLL?

Dense sheets of small lymphocytes.

What is the key clinical feature of early CLL?

Asymptomatic presentation.

How is CLL often discovered?

Incidentally on routine CBC showing lymphocytosis.

What is the most common presenting sign of CLL?

Painless lymphadenopathy.

What percentage of patients are asymptomatic at diagnosis?

Approximately 50%.

What organs are commonly enlarged in CLL?

Lymph nodes, spleen, and sometimes liver.

What causes splenomegaly in CLL?

Infiltration by malignant lymphocytes.

What is the pathophysiology of symptoms in CLL?

Bone marrow overcrowding leading to decreased normal cell production.

What is pancytopenia in CLL?

Decreased RBCs, WBCs, and platelets due to marrow failure.

What causes fatigue in CLL?

Anemia from decreased RBC production.

What causes bleeding in CLL?

Thrombocytopenia.

What causes infections in CLL?

Decreased normal WBCs and hypogammaglobulinemia.

What is hypogammaglobulinemia?

Reduced immunoglobulin production by normal B cells.

What is the most common cause of death in CLL?

Infection.

What autoimmune complication can occur in CLL?

Immune hemolytic anemia.

What is the typical prognosis of CLL?

Variable, but many patients live around 10 years.

What is the disease course of CLL?

Indolent early phase followed by progressive terminal phase.

What happens in late-stage CLL?

Increased marrow failure and complications.

What is the immunophenotype of CLL cells?

CD5+, CD19+, CD20+.

Why is CD5 expression unusual in CLL?

It is typically a T-cell marker but is expressed on CLL B cells.

What is the diagnostic value of immunophenotyping in CLL?

Confirms malignant B-cell population and distinguishes from benign lymphocytosis.

What is Richter transformation?

Transformation of CLL into aggressive diffuse large B-cell lymphoma (DLBCL).

How often does Richter transformation occur?

Approximately 3%–10% of cases.

What symptoms suggest Richter transformation?

Fever, weight loss, and night sweats (B symptoms).

What are B symptoms?

Fever, weight loss, and night sweats indicating aggressive disease.

What happens to lymph nodes in Richter transformation?

Rapid enlargement and bulky lymphadenopathy.

What is the prognosis of Richter transformation?

Poor, with median survival around 8 months.

What is seen on biopsy in Richter transformation?

Transition to large malignant B cells (DLBCL).

What is the hallmark clinical takeaway of CLL?

Indolent B-cell malignancy with lymphocytosis, smudge cells, and risk of infection and transformation.

What lab abnormalities are seen in CLL?

Elevated WBC count with lymphocytosis, low hemoglobin, and low platelets.

Why does anemia occur in CLL?

Bone marrow infiltration and possible autoimmune hemolysis.

Why do platelets decrease in CLL?

Marrow crowding and disease progression.

What is the role of bone marrow biopsy in CLL?

Provides diagnostic and prognostic information.

Why is cytogenetic testing important in CLL?

Determines prognosis and disease aggressiveness.

What is the hallmark morphologic clue for CLL on smear?

Smudge cells with mature lymphocytes.

What is the key clinical takeaway of CLL/SLL?

A chronic, often asymptomatic B-cell malignancy with lymphocytosis, immune dysfunction, and potential transformation to aggressive lymphoma.