Which condition is characterized by "smudged" appearing WBCs?

Chronic lymphocytic leukemia (CLL) is characterized by the presence of small, mature lymphocytes in the blood, often referred to as "smudge cells." These smudge cells are essentially fragile lymphocytes that have been disrupted during the process of blood smear preparation, leading to their characteristic appearance.

In CLL, the accumulation of these lymphocytes is due to a clonal proliferation of B-lymphocytes, which can crowd out normal hematopoiesis and contribute to various clinical symptoms, including lymphadenopathy and splenomegaly. The "smudged" appearance arises from the fragility of the CLL cells, which can easily break apart during the slide preparation process.

This unique feature helps distinguish CLL from other hematological conditions. In acute myeloid leukemia (AML), for example, one typically sees more immature myeloid cells rather than the mature lymphocytes seen in CLL. Prolymphocytic leukemia is characterized by larger lymphocytes and not by the smudge cell phenomenon. Myelodysplastic syndromes generally present with dysplastic features in the hematopoietic cells and do not typically show smudge cells either, as the issue involves ineffective hematopoiesis rather than a proliferation