80 year old, asymptomatic man present with a total leucocyte count of 1 lakh, with 80% lymphocytes and 20% PMCs. What is the most probable diagnosis?

Ans. is 'C' i.e., CLL Chronic lvmphocvtic leukemia (CLLVSmall lymphocyte lymphoma (SLL) o CLL and SLL are identical neoplasms/arise due to an abnormal neoplastic proliferation of B cells. CLL involves primarily bone marrow and blood, while SLL involves lymph nodes. Morphology of CLL/SLL o The tumor cells of CLL are small B lymphocytes. Leukemic cells have the morphological appearance of normal small to medium sized lymphocytes with clumped chromatin, inconspicuous nuclei and a small ring of cytoplasm. o The lymph node architecture is diffusely effaced by these tumor cells. These cells are mixed with variable numbers of larger cells called prolymphocytes. In many cases, prolymphyocytes gather together focally to form as proliferation centers, so called because they contain relatively large number of mitotic activity. When present proliferation centers are pathognomonic for CLL/SLL. o In CLL, the peripheral blood contains increased numbers of small, round lymphocytes with scant frequently disrupted in the process of making smears, producing So called smudge cells (Basket 'cells' or parachute 'cells'). Markers of CLL tumor cells o CLL is a tumor of mature B-cells, therefore it expresses the B-cell markers such as CDI9, CD20 and surface IgM and IgD. In addition CD 23 and CD5 are also present (In contrast to mantle cell lymphoma which is positive for CD5 but negative for CD23). Clinical features of CLL o Most patients present at ages over 50 with a male predominance. Patients with CLL are often asymptomatic. When symptoms appear, they are nonspecific and include easy fatigability, weight loss and anorexia. Other symptoms are # Hepatosplenomegaly # Hypogammaglobulinemia - Increased susceptibiltiy to infections. # Lymphodenopathy # Autoimmune hemolytic anemia or thrombocytopenia o CLL has a tendency to transform into more aggressive lymphoid neoplams:- i) Prolymphocytic leukemia - Characterized by worsening of cytopenia, marked splenomagaly and appearance of prolymphocytes in the peripheral blood. ii)Richiter syndrome - CLL is transformed into diffuse large B-cell lymphoma.