Solitary intraosseous neurofibroma of the mandible. Apropos of a case

Abstract

Neurofibroma is a benign neoplasm derived from peripheral nerves. Most of these are associated with Neurofibromatosis but may also occur as solitary lesions. When found on the head and neck they are generally located in the soft tissue. Intraosseous location is very rare. The following report describes a case of an intraosseous neurofibroma located in the left mandibular ramus of a 14-year-old child. The patient did not had clinical evidence of the lesion and it was found on a routine radiographic examination. Surgical excision of the lesion was scheduled and the sample was submitted to histopathological study. Representative sample cuts were studied using conventional techniques of hematoxylin-eosin and immunohistochemistry using primary antibodies anti S-100 protein, vimentin, and neuroespecific enolase. A review of clinical, radiographic, histologic and immunohistochemical features of other cases of intraosseuos neurofibromas located in the jaws together with the possible differential diagnosis of the lesion are discussed. Our case corresponds to a intraosseous neurofibroma of controveltial diagnosis because even though it presents typical neurofibroma histomorphological features it has immunophenotype different from usual.

Expression of S-100, EMA, CD34 and presence of mast cells in eight oral neurofibromas, and a review of 127 cases of the literature

“…In addition, the cell nuclei and cytoplasm in the present study exhibited frequent variations in the staining intensity, which corroborates the findings of Nascimento et al (7) . Neurofibromas are immunopositive for the S-100 protein in 85% to 100% of the occasions (19,32) , although rare findings of negative S-100 immunostaining can occur (6) , as seen in one case in the present study. In our series, none of the cases exhibited spindle cells whose nuclei or cytoplasm stained positive for EMA.…”

“…Immunohistochemistry (IHC) has been instrumental in confirming this heterogeneity and represents an auxiliary method in the diagnosis and identification of this neural tumor (6,15,29) . The S-100 protein marker has been widely used in the identification of Schwann cells and is important for the diagnosis of neural sheath tumors (30) .…”

Solitary intraosseous neurofibroma: Report of a unique case

“…[10] Our patient did not have café au lait spots on the trunk nor any other common clinical features suggestive of Von Recklinghausen's disease. Solitary neurofibroma is a benign, slow growing neoplasm, relatively circumscribed but not encapsulated, originating within a nerve and composed of Schwann cells, perineural cells and mature collagen.…”

Oral neural tumors: Clinicopathologic analysis of 157 cases and review of the literature

“…It is the first (6,7,9,10) or second (5,8, current study) most common ONT. In the majority of cases, it arises in soft tissues, while it is very rare to appear in the jaws (22). It usually appear in the palate, gingiva and tongue (5,11) and clinically presents as solitary and less frequently as multiple asymptomatic small sessile nodules covered by normal appearing mucosa (21).…”