Extranodal diffuse large B-cell lymphoma presenting with extensive organ involvement.

Extranodal involvement in diffuse large B-cell lymphoma (DLBCL) is defined as disease outside of the lymph nodes and occurs in up to one-third of patients, though multiorgan extranodal involvement is rare. Here, we describe a case of a patient presenting with widely metastatic lesions, including involvement of the lung, parotid gland, breast, pancreas, femur and multiple soft tissue masses, with initial concern for primary breast malignancy. Breast pathology and imaging were consistent with triple-expressor, double-hit stage IV high-grade B-cell lymphoma with extensive extranodal involvement. Extranodal involvement is a poor prognostic factor associated with high rates of treatment failure, and novel therapies targeting CD19 are currently being studied for relapsed and refractory DLBCL. Extranodal disease is a complex entity that can involve virtually any organ system and should be considered for new presentations of malignancy.