A 48 year old woman was admitted with a history of weakness for two months. On examination, cervical lymph nodes were found enlarged and spleen was palpable 2 cm below the costal margin. Her hemoglobin was 10.5 g/dl, platelet count 2.7 * 10^9/L and total leukocyte count 40 * 10^9/L, which included 80% mature lymphoid cells with coarse clumped chromatin. Bone marrow revealed a nodular lymphoid infiltrate. The peripheral blood lymphoid cells were positive for CD19, CD5, CD20 and CD23 and were negative for CD79B and FMC—7. The histopathological examination of the lymph node in this patient will most likely exhibit effacement of lymph node architecture by:
A. A pseudofollicular pattern with proliferation centers
B. A monomorphic lymphoid proliferation with a nodular pattern
C. A predominantly follicular pattern
D. A diffuse proliferation of medium to large lymphoid cells with high mitotic rate
Correct answer : D. A diffuse proliferation of medium to large lymphoid cells with high mitotic rate
The history, clinical features and immunophenotype is characteristic of chronic lymphoid leukemia.