Organizing pneumonia in patients with hematologic malignancies: A steroid-responsive lesion

Background: Organizing pneumonia (OP) is a distinct histopathologic lesion that occurs in a variety of clinical contexts. There have been occasional reports of OP occurring in patients with hematologic malignancies. Study objectives: To examine the association of OP with hematologic malignancies and to assess the clinical course of affected patients. Design: A retrospective review of our institutional experience of unexplained OP developing in patients with hematologic malignancies. Setting: Tertiary care, referral medical center. Patients: We identified 6 patients with a verified histopathologic diagnosis of OP and antecedent or concomitant diagnosis of a hematologic malignancy from the Mayo Clinic database (1995-2003). Clinical, radiologic, and outcome data were abstracted from records. Results: Underlying hematologic disorders included lymphoma (2), acute leukemia (2), cutaneous T-cell lymphoma (1), and myelodysplastic syndrome (1). OP was diagnosed by surgical lung biopsy in 4 and bronchoscopic biopsy in 2. Four of the 6 patients had previously been exposed to chemotherapeutic agents, two had not. Three of the 6 patients had bone marrow transplantation prior to development of OP. Five patients were treated with prednisone and all experienced symptomatic improvement with documented radiologic resolution in 4. One patient experienced symptomatic and radiologic resolution with observation alone. Three patients ultimately died from complications of their underlying hematologic disorder and 1 patient died of unknown causes. Two patients were alive without respiratory complaints more than 1 year after lung biopsy. Conclusions: OP occurs in patients with underlying hematologic malignancies who may or may not have been treated with chemotherapy and responds favorably to corticosteroid therapy.