[A Case of Bilateral Adrenal Incidentaloma in which MTX-Related Lymphoproliferative Disease Could Be Diagnosed by Computed Tomography-Guided Biopsy and MTX Administration History].

The patient was a 76-year-old man. Because bilateral adrenal tumor (right adrenal gland 7 cm, left adrenal gland 1.5 cm) was detected in by computed tomography (CT) in methotrexate (MTX) administration for articular rheumatism from 2011, he was referred to this hospital in February, 2016. An endocrine examination, and imaging study did not lead to a definitive diagnosis and CT-guided lower needle biopsy was performed. The pathological diagnosis was diffuse large B cell lymphoma. Also, in situ hybridization revealed EBER-positive and the diagnosis of MTX-related lymphoproliferative disease (MTXLPD) was made in conjunction with the medical history. After MTX cancellation, the tumor became markedly smaller. The annual incidence of this disorder in the RA patients during MTX internal use is reported as 0.06%. According to the site of origin, lymphatic extranodal disease accounts for approximately half of the cases, but this is the third case of primary adrenal origin reported.