B cell lymphomas are heterogeneous malignancies of hematological origin with vastly different biology and clinical outcomes. Histopathology of tissue biopsies and image-based assessment guide clinical decisions. Given that tissue biopsies cannot be frequently repeated and will not inform on systemic responses to the treatment, more accessible biomarkers, such as circulating miRNAs, are considered. Aberrant miRNA expression in lymphoma tissues and ongoing immune reactions may lead to miRNA alterations in circulation. miRNAs bound to extracellular vesicles (EVs) are of interest because of their role in intercellular communication and organ crosstalk. Herein, we highlight the role of miRNAs and EVs in B cell lymphomagenesis and explain how circulating miRNAs may be turned into robust liquid biopsy tests for aggressive B cell lymphoma.