With the recent introduction of inhibitors of mammalian target of rapamycin 
(mTOR) in oncology, distinct cutaneous and oral adverse events have been 
identified. In fact, stomatitis and rash are documented as the most frequent and 
potentially dose-limiting side effects. Clinically, mTOR inhibitor-associated 
stomatitis (mIAS) more closely resembles aphthous stomatitis than oral mucositis 
due to conventional anticancer therapies. While most cases of mIAS are mild to 
moderate and self-limiting, more severe and persistent mIAS can become a 
dose-limiting toxicity. Small ulcerations may cause significant pain and mucosal 
sensitivity may occur in the absence of clinical changes. Use of clinical 
assessment tools that are primarily driven by ulceration size may underestimate 
mIAS, and assessment should include patient-reported outcomes. This article 
provides an up-to-date review of the clinical presentation, terminology, 
pathogenesis, assessment and management of mIAS and other mTOR 
inhibitor-associated oral adverse events. In addition, areas of future research 
are considered.