Abstract
A 69-year-old woman had been treated with methotrexate (MTX) for 4 years for rheumatoid arthritis, and she presented with multiple lymphadenopathy and a left breast mass. Fine-needle aspiration cytology was performed for a lymph node above the collarbone and it was pathologically diagnosed as diffuse large B cell lymphoma, MTX-related lymphoproliferative disorder (MTX-LPD). MTX was withdrawn, and a follow-up computed tomography scan obtained 4 weeks later showed shrinkage of the lymph nodes. The left breast mass was diagnosed as breast cancer (invasive ductal carcinoma) by core needle biopsy. The patient underwent partial mastectomy and sentinel lymph node biopsy (SLNB) with technetium-99 and patent blue, which was negative. Final pathology confirmed the absence of SLN metastases. Despite the axillary lymph nodes being swollen, we were able to accomplish sentinel lymph node SLNB without any complications.
