Megaloblastic Anemia Due To Intrathecal Methotrexate

We diagnosed to the patient as primary mediastinal CD20 positive diffuse large B-cell lymphoma two years ago. The patient received R-CHOP chemotherapy. Complete remission was obtained from chemotherapy. After 18 months, headache, nausea and vomiting occurred. Cranial magnetic resonance imaging showed mass lesions. Cranial radiotherapy was applied. Then intrathecal methotrexate (MTX) was administered at a dose of 12 mg via lumbar puncture twice weekly for 6 weeks. Pancytopenia was detected after ten days of the discontinuation of intrathecal MTX. There were apparent megaloblastic changes on the bone marrow aspiration and biopsy. The biochemical parameters were folic acid 6.22 ng/ml (N:4.2-19.99) and cobalamin 803 pg/ml (N:197-866). The patient was treated with oral folic acid 5 mg/day. Hematological parameters were hemoglobin 10.2 g/ dl, platelet count 432 000/mm3, and leukocyte count 5100/mm3 at the 14th day. In conclusion, the patients treated with intrathecal MTX should be followed-up and folic acid prophylaxis may be considered. Iki yil once primer mediastinal CD20 pozitif yaygin buyuk B hucreli lenfoma tanisi koydugumuz hasta, R-CHOP kemoterapisi aldi. Kemoterapiden sonra tam yanit elde ettik. On sekiz ay sonra bas agrisi, bulanti ve kusma sikayetleri basladi. Kraniyel magnetik goruntulemede kitle tespit edildi. Kraniyel radyoterapi uygulandi. Haftada 2 kez 6 hafta sureyle lumbar yolla 20 mg intratekal methotrexate (MTX) verildi. Intratekal methotrexate kesildikten 10 gun sonra pansitopeni gelisti. Kemik iligi aspirasyon ve biyopsisinde megaloblastik degisiklikler gozlendi. Biyokimyasal degerlerinde folik asid 6.22 ng/ml (N:4.2-19.99) ve kobalamin 803 pg/ ml (N:197-866) idi. Oral folik asit 5 mg/gun bas - landi. Ondorduncu gunde hemoglobin 10.2 g/ dl, platelet sayisi 432 000/mm3ve lokosit sayisi 5100/mm3 idi. Sonuc olarak intratekal methotrexate ile tedavi edilen hastalarda takip ve folik asit profilaksisi dusunulebilir.