Unusual Case of a Proptosed Eye: Isolated Right Maxillary Neurofibroma

Abstract

Neurofibroma is a slow growing benign tumour of the peripheral nerve sheath which is frequently associated with neurofibromatosis type 1 (Prakash et al., 2014). Isolated solitary occurrence of neurofibroma in the maxillary sinus is rare with only 29 reported cases in the literature. We present a rare case of a 70-year-old gentleman who was referred to ENT with a right maxillary sinus neurofibroma with extension into the right inferior orbit. He has significant proptosis, ptosis, and limitation in abduction of the right eye. He has a complicated past history of multiple neurofibromas which were completely excised. Craniofacial MRI shows a large mass filling the right maxillary antrum extending anteriorly into subcutaneous tissue towards nasal ala and posterolaterally into inferior temporal fossa and superiorly into orbit and cavernous sinus involvement. Biopsy of the right maxillary mass revealed cellular spindle cell tumour with wavy collagen bundles within myxoid stroma which is consistent with a neurofibroma. Patient's case was discussed in the skull-base MDT and he has been referred to a specialist center for surgical removal of the neurofibroma with reconstructive surgery. Despite the rarity of this disease, otorhinolaryngologist should consider a possibility of neurofibroma of the paranasal sinuses.

Unusual paranasal sinus solitary neurofibroma and literature review

“… 2,3 Most paranasal sinus NFs are primary solitary lesions (90%), with only a few related to type I neurofibrosis (10%). 4,5 …”

“…Clinical manifestations of sinus NF lack specificity and vary depending on location. Common clinical manifestations include local swelling, pain, nasal congestion or runny nose as well as epistaxis or facial discomfort; occasionally invading the orbit can lead to exophthalmos and visual impairment, 4 invading alveolar bone can lead to tooth loosening or abnormal occlusion, 2 and invading brain tissue can cause headaches. 17 Solitary NFs differ from NF1 related ones due to lack of common skin coffee spots or family history associated with them.…”

Voluminous Solitary Neurofibroma of the Nasosinus Cavities in an Undermedicalized Context: Reflection on a Case Collected in Bamako

“…Neurofibromas are benign, slow growing, and relatively circumscribed but not encapsulated peripheral to the nerve sheath arising from non-myelinating Schwann cells [5]. Involvement of the nasosinusian cavities is rare and found in 4% of cases [6]. The neurofibroma would develop from the 1st and 2nd dividing branches of the trigeminal nerve destined for different structures of the naso-sinus cavities, in particular the septum, the turbinates, the maxillary sinus.…”

“…In nose and paranasal sinuses [12]. In general, the differential diagnosis of neurofibroma of the nasosinusian tract must be made in order of frequency with schwannomas, protuberant dermatofibrosarcomas, fibrosarcomas, meningiomas, leiomyomas, solitary fibrous tumors, leiomyosarcomas [6]. Only immunohistochemistry is useful in this respect to avoid diagnostic errors.…”

“…In this, we performed a total excision of the mass via the paralateronasal route, even if the current trend in the literature is surgical resection via the endonasal route. Recurrence is possible even if its frequency remains low and malignant transformation is rare [6,14]. Indeed, only a few cases of malignant degeneration have been described in the literature [10,14].…”