702 - Rehabilitating Hope: Functional Outcomes in a Rare Case of Multicentric Castleman Disease

Case Diagnosis: This is a rare and complex case of HIV Negative, HHV-8 Negative Idiopathic Multicentric Castleman Disease.

Case Description: A 77-year-old previously independent male was diagnosed with idiopathic multicentric Castleman disease (iMCD) after a positive left axillary lymph node biopsy and negative HIV and HHV-8 tests. He was initially treated with siltuximab, which was subsequently held due to thrombocytopenia. Dexamethasone and romiplostim were started without resolution of thrombocytopenia. The patient was admitted to acute care with persistent thrombocytopenia, hypotension, and kidney failure. He received dialysis for glomerulopathy, and intravenous immunoglobulin and methylprednisolone for immune thrombocytopenia purpura (ITP). He was admitted to inpatient rehabilitation (IPR) due to impaired functional capacity. While in IPR, he required allopurinol to prevent tumor lysis syndrome, midodrine for hypotension, and a multimodal pain regimen. On discharge from IPR, the patient had progressed from requiring moderate to maximum assistance for activities of daily living to back to his baseline independence.

Discussions: Castleman disease is a rare lymphoproliferative disorder that can cause unicentric (single lymph node involvement) or multicentric (multiple lymph node involvement) disease. IMCD must be negative for HIV and HHV-8 as an underlying cause of the disease. For this patient, autoimmune phenomena secondary to Castleman disease likely led to ITP, glomerulopathy, subclinical autoimmune hemolytic anemia, and subsequent functional decompensation. This patient successfully completed rituximab treatment once siltuximab had to be discontinued.

Conclusions: This case is unique case because iMCD is a rare diagnosis and there is minimal literature on the functional benefits of an IPR stay. This patient gained significant functional recovery and continues to follow up with physiatry outpatient, demonstrating that early and continued involvement of physiatry in patients with Castleman disease can significantly improve quality of life and functional outcomes.