Idelalisib and Rituximab in 17p Deletion-Positive Splenic Marginal Zone Lymphoma.

Splenic marginal zone lymphoma (SMZL) is a rare indolent B-cell malignancy involving the spleen and bone marrow. Various cytogenetic abnormalities with prognostic value have been identified in SMZL. Complexity of karyotype, 14q aberrations, and TP53 deletions have been found to be poor prognostic indicators. We report an unusual case of SMZL with a complex karyotype including 17p deletion, primarily refractory to 2 chemoimmunotherapy regimens, that responded well to treatment with phosphatidylinositol-3-kinase delta (PI3Kδ) inhibitors idelalisib and rituximab.