A 48 years of 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 10.5g/di. Platelet count 237x 109/L, and total leukocyte count 40×109/L, which include 80% mature lymphoid cell with coarse clumped chromatin. Bone marrow revealed dnodular lymphoid infiltrate. The peripheral blood lymphoid cells were positive for CD19, CD5, CD20 and were negative for CD79B and FMC(-7). Which one of the following statements is not true about this disease?

**Core Concept**
The patient's presentation and laboratory findings are characteristic of a specific type of lymphoproliferative disorder, specifically Chronic Lymphocytic Leukemia (CLL). CLL is a malignancy of mature lymphocytes, typically presenting with an absolute lymphocytosis, lymphadenopathy, splenomegaly, and abnormal lymphocyte morphology.

**Why the Correct Answer is Right**
The patient's peripheral blood lymphoid cells are positive for CD19, CD5, and CD20, which are characteristic markers for CLL. The absence of CD79B expression is also consistent with CLL, as CD79B is a component of the B-cell receptor complex and is often downregulated in CLL cells. The FMC7 marker is also negative, which is a common feature of CLL. The bone marrow biopsy showing a nodular lymphoid infiltrate is also consistent with CLL.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is true about CLL, as it is a common feature of the disease. CLL cells often exhibit a mature, lymphoid appearance with coarse clumped chromatin.
**Option B:** This statement is true about CLL, as the disease is characterized by an absolute lymphocytosis, with lymphocytes accounting for > 80% of the peripheral blood leukocytes.
**Option C:** This statement is true about CLL, as the disease often presents with lymphadenopathy and splenomegaly due to the accumulation of malignant lymphocytes in these organs.
*Option D:* This statement is not true about CLL. CLL is characterized by a monoclonal proliferation of mature lymphocytes, whereas CLL cells often exhibit a complex karyotype with multiple chromosomal abnormalities, including deletions and translocations.

**Clinical Pearl / High-Yield Fact**
In CLL, the FMC7 marker is often negative, which can be used to differentiate CLL from other types of B-cell lymphoproliferative disorders.

**Correct Answer: D. CLL cells often exhibit a complex karyotype with multiple chromosomal abnormalities.**

✓ Correct Answer: D. t(11;14) translocation is present in most of the cases