To prevent MTX toxicity, liver and renal function should be assessed and a complete blood cell count should be performed before starting therapy. These tests should be repeated during treatment to monitor for MTX toxicity.
Leucovorin (folinic acid) counteracts MTX-induced epidermal necrosis by neutralizing the effect of MTX, including antitumoral effectiveness of the drug.8 For that reason, leucovorin cannot be started prophylactically.
The main challenges that we encountered in our patient's case were the rarity of reports of AITL in the literature and failure of 3 different lines of chemotherapy previously, which meant that MTX could not possibly be suspended because the drug represented the last therapeutic option. Our case confirms that timely clinical diagnosis and a rapid combined approach consisting of discontinuation of MTX and initiation of leucovorin rescue therapy represents an effective strategy to prevent further toxicity and to alleviate mucositis, even in patients with this rare subset of lymphoma.