S m a l l L y m p h o c y t i c L y m p h o m a
General
SLL is identical to chronic lymphocytic leukemia (CLL) morphologically, immunophenotypically, and clinically. Artificial distinction: SLL=nodal, CLL=bone marrow/blood. Most people now think of these as the same disease.
Morphology
• Pattern: Diffuse, with proliferation centers.
• Cytology: small, round lymphocytes with clumped chromatin, scant
cytoplasm (look just like benign, mature lymphocytes!).
• Proliferation centers (cloud-like in low-power appearance; contain
prolymphocytes and paraimmunoblasts, with fine chromatin and prominent
nucleoli) are diagnostic of SLL.
Immunophenotype
• B cell…
• …but with aberrant expression of CD5!
Clinical features
• Indolent but relentless clinical course (mean survival = 10 years).
• Some cases evolve into a large-cell lymphoma (Richter's transformation).
