Primary Central Nervous System Immunomodulatory Therapy-Induced Lymphoproliferative Disorder in a Patient with Ulcerative Colitis: A Case Report and Review of the Literature

BACKGROUND: Immunosuppression and immunomodulatory therapy-induced lymphoproliferative disorders (ILPD) represent a heterogeneous group of lymphoid cell disorders that occur secondary to iatrogenic immune dysfunction, best described in the post-transplant setting. CASE DESCRIPTION: We describe a case of a primary central nervous system ILPD in a patient with ulcerative colitis treated chronically with the immunomodulatory agents infliximab and azathioprine. This 52-year-old woman presented with a 1-month history of left-side weakness and paresthesias. Neuroimaging identified multiple heterogeneously enhancing lesions in her cerebrum. Extensive systemic infectious and malignancy-related investigations were negative, prompting neurosurgical referral to obtain a tissue diagnosis. Pathologic assessment of her open excisional biopsy specimen confirmed the diagnosis of a polymorphic lymphoproliferative disorder. She was treated by withdrawal of infliximab and azathioprine, along with a prolonged course of prednisone. At her 6-month follow-up, she demonstrated both clinical and radiologic improvement. CONCLUSIONS: ILPD should be considered in the differential diagnosis in patients with iatrogenic immunodeficiency presenting with neurologic symptoms and intra-axial mass lesions on neuroimaging investigations. A standard treatment regimen for ILPD remains to be determined, however withholding the immunomodulatory agents and trial of corticosteroids may be tried as a first-line option before the use of more aggressive chemotherapy and/or radiotherapy.