April 2002: 35-year-old healthy man with enlarging right parotid mass

Solitary oral plexiform neurofibroma: review of literature and report of a case

Plexiform neurofibroma (PN) is a rare, benign tumor of nerve sheath origin, which frequently manifests as part of neurofibromatosis type 1. The article presents a case of solitary PN in a 4-year-old girl, which manifested as a double lip and without systemic or familial involvement. A review of the literature on solitary PN in the oral soft tissue demonstrates the scarcity of such cases.

Intra-parotid facial nerve multiple plexiform neurofibroma in patient with NF1

INTRODUCTION

Primary neurogenic tumours of facial nerve are uncommon with the majority found intra-temporally. Intracranial and intra-parotid neoplastic involvement of cranial nerve VII is much less common. There are 11 reported cases, in the English-language literature, of intra-parotid facial nerve plexiform neurofibromas with eight of them associated with NF1.

MATERIALS AND METHODS

A child, 10 years old, with NF1, reached us for a cheek swelling, slowly increased in previous 8 years. At the age of 3 years, a plexiform neurofibroma was diagnosed by biopsy of the lesion. Clinical examination and NMR showed in the sub-cutaneous tissue of the right cheek, two contiguous nodular lesions, about 2 cm x 1.5 cm in diameter; a third neoformed lesion, about 1cm in diameter, was located above the ipsilateral labial commissure. No facial nerve impairment was seen. The patient underwent superficial parotidectomy with removal of the lesions and preservation of the facial nerve.

RESULTS

The patient had a considerable regional swelling in the immediate post-operative course; no facial nerve impairment was observed. The swelling of the cheek did not show a fully regression in the post-operative course. Ultrasonography at 3 months showed a recurrence of disease.

DISCUSSION

Plexiform neurofibromas should be distinguished due to their risk of malignant transformation seen in up to 15% of patients affected by NF1. Surgery is the only effective option currently available for the treatment of PNF. However, success of surgical intervention is limited by the infiltrating nature of the tumours, resulting in a high rate of tumour re-growth. Facial nerve preservation during surgery is unlikely and significant morbidity can result from their excision. The age of the patient at surgical resection seemed to influence outcome: tumours resected before age 10 years recurred in 60% of cases compared with only 30% recurrence in patients older than the age of 10 years.

CONCLUSION

Indication and timing of surgery, in paediatrics patients with NF1, are complex. To avoid eventual physical and psychological consequences, it seems prudent to delay surgery as long as it is feasible for otherwise asymptomatic paediatric patients with facial plexiform neurofibroma.

[Solitary intraparotid neurofibroma of the facial nerve. Symptomatology, biology and management]

Neurogenic neoplasms of the parotid gland are extremely uncommon. We present the case of a solitary intraparotid neurofibroma of the N. facialis occurring in a 55-year-old female who noted a painless left-side enlargement in the region of the parotid gland over a period of 2 years. Facial function was normal. Magnetic resonance imaging revealed a well-demarcated round mass within the left parotid. At surgery, a tumor was found involving the main trunk of the facial nerve, histopathologically representing a neurofibroma. Since solitary intraparotid neurofibromas are characterized by a very slow growth lacking the propensity for malignant transformation, the tumor was left to preserve facial nerve function. The clinical course over months or even years and the non-specific symptomatology are characteristic of intraparotid facial neurofibromas. Surgical management depends on the clinical setting in the individual case. Conservative treatment based on facial nerve preservation and leaving the tumor in situ is recommended, rather than radical tumor removal with resection of the segment of the N. facialis involved.