Conclusion
Intravascular B-cell lymphoma has traditionally been associated with an aggressive course and poor outcomes. Recent efforts to increase awareness and improved insight into the disease have led to increased identification of this disorder. However, it remains an elusive diagnosis due to heterogeneity in presentation. The development of IVLBCL in two of our patients on active immunosuppression could point towards an underlying disease mechanism similar to that seen in the development of post-transplant lymphoproliferative disorder. Traditional preliminary diagnostic modalities such as imaging are usually inconclusive, given the paucity of lymphomatous aggregates. A bone marrow biopsy, random skin biopsies, or a focal organ biopsy in appropriate cases is required for diagnosis. Nevertheless, a timely diagnosis requires a high clinical suspicion. Early initiation of aggressive anthracycline-based therapy with rituximab is associated with improved outcomes. Novel treatment approaches such as end-organ resection, if the disease is limited to a single organ such as thyroid or kidney, can potentially induce remission without the need for systemic therapy.