Intraoral Neurinoma of the Lingual Nerve: An Uncommon Tumor in Floor of the Mouth

Neurinoma or schwannoma is an uncommon benign tumor that arises primarily from the nerve sheath of Schwann cells. About 25% has been reported in head and neck region extracranially, but only 1% in the intraoral origin. Intraorally, the tongue is the most common site followed by the palate, floor of the mouth, lips and buccal mucosa. In review of literature, intraoral schwannoma of the lingual nerve origin has not been reported frequently. So, we present a case of intraoral neurinoma of the lingual nerve. 1. Introduction Schwannoma/neurinoma is a nerve sheath tumor that originates from the Schwann cells of peripheral, cranial, and autonomous nerves. It is a slow growing benign tumor, mostly asymptomatic in nature. It frequently appears as a solitary encapsulated swelling, except the neurofibromatosis type which occurs as multiple lesions [1]. Malignant transformation of the lesion is extremely rare, making complete surgical excision to be the treatment of choice [2]. Incidence of neurinoma in the intraoral region is about only 1%, in which tongue is the common site followed by palate, floor of the mouth, lips, and buccal mucosa [1–4]. In the literature, there are reported cases of neurinoma/schwannoma originating from the mylohyoid nerve, hypoglossal nerve, and sublingual gland, but there are a very few literatures on schwannoma originating from the lingual nerve [1]. Subhashraj et al. reviewed the English medical literature and concluded that, including their case, till now only eight cases of ancient schwannoma have been reported with a maximum diameter of 31？mm in males and 55？mm in female patients [4]. Here we present a very rare case of neurinoma from the lingual nerve with a rapid growth in a relatively shorter duration and a review of the literature. 2. Case Report A thirty-one-year old female patient reported to the Department of Oral and Maxillofacial Surgery with a swelling in the floor of the mouth for the past two months. The swelling was initially small and gradually reached the present size over two months. On extraoral examination, a diffuse swelling in the left submandibular region was present. On intraoral examination, a single well-defined encapsulated swelling was present in the left side of floor of the mouth (Figure 1). On palpation, the swelling was tender, firm, and nonfluctuant and the swelling extends anteroposteriorly from the midline of the floor of the mouth to the second molar region in the left side of the mandible (Figure 1). Patient was having altered sensations in the left lateral border of tongue and the lingual