Minimal Residual Disease (MRD) in Indolent Lymphomas

Minimal residual disease (MRD) detection is a broad term that indicates a number of methods suitable to detect the persistence of residual tumor cells below the sensitivity of standard diagnostic tools. Several tools are currently employed, including polymerase chain reaction (PCR) and flow cytometry. More modern approaches, such as those based on next-generation sequencing, are gaining considerable role in the current years. MRD detection provided a considerable amount of knowledge in several subtypes of indolent lymphoma and is regarded as a reliable outcome predictor in multiple settings. This chapter describes the rationale, the technical methods, and the clinical relevance of MRD detection in indolent lymphomas, mantle cell lymphoma, and chronic lymphocytic leukemia.