Intravascular large B-cell lymphoma presenting as unilateral lymphedema in a patient with rheumatoid arthritis and sarcoidosis: A case report.
Kimura Masatoshi M, Sasaki Haruka H, Kudo Risa R, Murai Masayuki M et al.
Intravascular large B-cell lymphoma (IVLBCL) is an uncommon subtype of diffuse large B-cell lymphoma, typically presenting with nonspecific symptoms and lacking lymphadenopathy or visible tumor lesions, which makes early diagnosis challenging. A 66-year-old female developed progressive unilateral lymphedema despite ongoing treatment for rheumatoid arthritis and sarcoidosis. Sarcoidosis-related lymph node lesions were also considered as a potential cause, and the prednisolone dose was increased. Despite these measures, the edema worsened, and a fever of around 38°C developed. At the initial evaluation, the serum soluble interleukin-2 receptor level was already elevated at 9985 U/mL. Initial investigations, including imaging, bone marrow aspiration, and random skin biopsies, failed to reveal malignancy. Subsequent monitoring revealed that the serum level of serum soluble interleukin-2 receptor had risen further to 19,835 U/mL and that thrombocytopenia was present, prompting a repeat random skin biopsy that ultimately confirmed IVLBCL through the identification of intravascular cluster of differentiation 20-positive lymphoma cells. Chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone was initiated. However, the patient developed peripheral neuropathy, suspected to be an adverse drug reaction. Consequently, the regimen was switched to polatuzumab vedotin, rituximab, cyclophosphamide, doxorubicin, and prednisolone. After completing 8 courses, the patient achieved remission. The left lower-limb lymphedema improved significantly. This case highlights several clinically significant points: first, IVLBCL can present solely as unilateral lymphedema without detectable lymph node enlargement or tumorous lesions, underscoring the diagnostic difficulty. Second, repeated random skin biopsies, including adipose-rich vascular tissue, are crucial in establishing a definitive diagnosis when initial biopsies are inconclusive. Third, patients with underlying autoimmune conditions such as rheumatoid arthritis and sarcoidosis, particularly those receiving immunosuppressive therapies, may have an increased susceptibility to lymphoma, suggesting that systemic immune dysregulation could contribute to disease onset.