Abstract
Head and neck schwannomas comprise 25-40% of all schwannomas, with presentation on the lips as the rarest and most surgically complicated site for perioral tumors. A systematic literature review was conducted to include 21 cases of patients with schwannoma of the upper or lower lips. The majority of patients presented with a single, painless, well-encapsulated nodule on the upper or lower lips. The nodules were consistently slow-growing, with an average 29.3 months from symptom onset to clinical presentation. Most cases were complicated by profound cosmetic disfigurement as well as dysphagia, dysarthria, snoring, and/or sleep apnea. Overall, histological analysis was consistent with classic schwannoma, and all cases were treated via complete surgical excision, and for malignant tumors, additional therapy was utilized. All but four cases achieved full remission by final follow-up. Recurrence rate for benign lip schwannomas was 5.3%, which is remarkably different from the standard recurrence rate of 8-24% for benign peripheral schwannomas. Additionally, the proportion of malignant tumors was greater for lip schwannomas than other schwannomas. Lip schwannomas demonstrate different characteristics than schwannomas from other locations on the body, and these remarkable differences highlight significant implications for clinical practice. Complete excision is the primary mode of treatment with overall excellent postoperative prognosis and rare instances of recurrence. Given the rarity of this tumor, this review of available cases serves to comprehensively describe clinical presentation and surgical treatment approaches to upper and lower lip schwannomas.