Plexiform Schwannoma: An Upper Lip Swelling With an Unexpected Diagnosis

ABSTRACT Aim Schwannomas are rare benign, usually solitary tumours of the nervous system, with a predilection for adults in their fourth decade of life. Though the head and neck area accounts for about 25% to 45% of all schwannomas, the upper lip is an extremely uncommon location. Here we report a case of a plexiform schwannoma presenting as an upper lip swelling in a 23‐year‐old male. Materials and Methods The lesion presented as a longstanding, asymptomatic, firm and mobile submucosal lump on the left‐hand side of the upper lip, seen both intra‐ and extra‐orally. Due to the location and clinical features a provisional diagnosis of a benign minor salivary gland tumour, such as pleomorphic adenoma was considered, and an excisional biopsy arranged. Results The microscopic and immunohistochemical examination confirmed the diagnosis of a plexiform cellular schwannoma with no evidence of malignancy. Conclusion Less than 20 schwannomas have been reported in the English literature as located on the upper lip. Moreover, plexiform schwannomas are an uncommon variant with a predilection to arise in the skin, thus making the upper lip an extremely rare location. This case illustrates the broad range of pathology that can present as lesions of the upper lip.