Methotrexate-Associated Lymphoproliferative Disorders Mimicking Granulomatosis With Polyangiitis: A Radiological Diagnostic Challenge

Abstract

Methotrexate-associated lymphoproliferative disorders (MTX-LPD) frequently involve the extranodal organs throughout the body. Among the extranodal occurrences of MTX-LPD, pulmonary involvement is most frequent. In contrast, there are only a few reports of MTX-LPD in the nasal cavity or paranasal sinuses. Moreover, there are no previous reports of MTX-LPD mimicking granulomatosis with polyangiitis (GPA) in imaging examinations. We describe a case of a 53-year-old woman with MTX-LPD mimicking GPA in the nasal cavity and lungs. She complained of left nasal obstruction and discharge, general fatigue, and continual fever for 2 months. The patient had been diagnosed with rheumatoid arthritis and received methotrexate (MTX) for over 10 years. Contrast-enhanced computed tomography revealed unenhanced masses in the nasal cavity and multiple masses with cavitary changes in the bilateral lungs, suggesting GPA. However, histological examination of the nasal lesion and a history of MTX treatment indicated a diffuse large B-cell lymphoma type MTX-LPD. Two weeks after MTX withdrawal, prominent improvements in both lesions were observed. Complete regression of the nasal lesion was observed 3 months after discontinuation of MTX. Thus, MTX-LPD may mimic GPA in imaging examinations.

Diffuse large B-cell lymphoma mimicking granulomatosis with polyangiitis and otitis media with antineutrophil cytoplasmic antibodies-associated vasculitis

“…[ 3 ] Some reports have described cases of ML mimicking GPA with craniocervical or otolaryngologic manifestations, such as sinusitis, otitis, nasal obstruction and discharge, masses in the nasal cavity, hypertrophic pachymeningitis and infarction of the pons. [ 4 , 5 ] Although GPA was suspected due to craniocervical or otolaryngologic manifestations in these patients, no kidney involvement was found. [ 4 ] Malignant lymphoma should, thus, be considered in patients without typical presentations such as glomerulonephritis, but differentiating between the two entities is practically difficult.…”