A Case of Methotrexate-induced Other Iatrogenic Immunodeficiency-associated Lymphoproliferative Disorders Diagnosed by an Endobronchial Biopsy

Abstract

Background. Methotrexate (MTX) is commonly prescribed in the treatment of rheumatoid arthritis leading to long-term usage, which then may be associated with a variety of pulmonary lesions. This is a case report of a woman with a 23-year history of taking MTX. Case presentation. A 65-year-old woman had a history of rheumatoid arthritis that had been diagnosed at age 26 years old. She had began treatment with MTX at age 43 years old. She presented to our hospital with a 7-day history of a fever and cough, and initial chest radiography showed multiple nodular shadows of unequal size in the right middle and lower lung fields. Subsequent computed tomography of the chest detected multiple nodular lesions in both lungs and enlarged lymph nodes in the left submandibular, upper mediastinum, and subtracheal bifurcation. Blood tests showed elevated levels of C-reactive protein and soluble interleukin-2 receptor as well as decreased lymphocyte counts. Bronchoscopy revealed a white, irregular, raised lesion in the trachea at the tracheal bifurcation. A direct visual bronchoscopic biopsy of this lesion and a percutaneous biopsy of the enlarged left submandibular lymph node revealed the dense proliferation of small to medium-sized lymphocytes, suggestive of other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPD) (MTX-associated lymphoproliferative disorders) of T-cell origin. Conclusion. An endobronchial biopsy was useful for diagnosing of OIIA-LPD induced by MTX. Bronchoscopy should be performed when pulmonary involvement is suspected on radiographic imaging, and direct visual biopsy should be performed when airway involvement is detected on bronchoscopy.