2018 Volume 111 Issue 2 Pages 139-146
Methotrexate (MTX) is recognized as a standard therapeutic drug for rheumatoid arthritis (RA). However, with long-term treatment, patients can occasionally develop severe complications, including malignant lymphoma (MTX-related malignant lymphoma). Herein, we report 2 cases of malignant lymphoma of the head and neck, presenting more than 2 years after the start of MTX treatment for RA. Case 1 was a female in her 50s who presented with enlarged, non-tender cervical lymph nodes. Lymph node excision biopsy revealed the diagnosis of typical Hodgkin lymphoma, based on the detection of characteristic Reed-Sternberg cells. Case 2 was a female in her 60s with a past history of iterate and chronic right parotitis, who presented with a soft and solid ipsilateral parotid mass. Biopsy of the right parotid mass revealed MALT lymphoma with clear B cell characteristics of the tumor cells. Considering the possible causal involvement of Epstein-Barr virus (EBV), in-situ hybridization of the lymphoma tissues was performed in both cases, which revealed a positive result for EBV-encoded RNA (EBER) in Patient 1. The tumors in both cases failed to resolve even after discontinuation of MTX, and the patients were immediately referred to our hematology/oncology department for further treatment. Patient 1 was administered chemotherapy with a multi-drug combination regimen, and Patient 2 was treated by topical external beam radiation (38 Gy in 20 fractions) for the parotid tumor. Both patients showed satisfactory response to the respective treatments and have shown no evidence of recurrent disease until now. In this article, we wish to emphasize that it is important for otorhinolaryngologists to bear in mind the possibility of MTX-related malignant lymphoma in the differential diagnosis of head and neck masses, particularly in cases of RA treated with MTX.
