Year : 2009 | Volume
: 27 | Issue : 1 | Page : 62--64
Intraosseous neurofibroma of maxilla in a child
P Sharma, A Narwal, AS Rana, S Kumar
Subharti Dental College, Meerut, India
C/o Mr. Harish Chandra Sharma, Bhagirath Bhavan, Near police station, G.T. Road, Khatauli-251 201
Central tumors of neurogenic origin are among the most rare primary jaw tumors in children. Intraosseous neurofibromas of the jaws occur more often as solitary lesions rather than as part of a generalized neurofibromatosis. We are presenting a case of solitary intraosseous neurofibroma of the maxilla in a five-month-old infant, which is probably the youngest such case published in literature so far.
|How to cite this article:|
Sharma P, Narwal A, Rana A S, Kumar S. Intraosseous neurofibroma of maxilla in a child.J Indian Soc Pedod Prev Dent 2009;27:62-64
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Sharma P, Narwal A, Rana A S, Kumar S. Intraosseous neurofibroma of maxilla in a child. J Indian Soc Pedod Prev Dent [serial online] 2009 [cited 2020 Feb 19 ];27:62-64
Available from: http://www.jisppd.com/text.asp?2009/27/1/62/50822
A solitary neurofibroma is a single lesion that occurs in an individual who does not have hereditary neurofibromatosis. The condition may at first be difficult to identify because a single neurofibroma may be the first sign of neurofibromatosis. In addition, the hereditary history of neurofibromatosis may be lacking because of the high incidence of new cases, due to spontaneous mutations.  Nevertheless, solitary neurofibromas account for 90% of all such cases.
Intraosseous occurrence of solitary neurofibroma in the head and neck is comparatively rare, with the most common site being the mandible.  A solitary neurofibroma of the maxilla has been reported only seven times in the literature in the last 20 years (Pubmed search). We report an additional case of solitary neurofibroma in the maxilla in an infant, with a one-year follow up postoperatively.
A five-month-old male child was brought to the Department of Oral and Maxillofacial Surgery by his parents, with a painless swelling in the anterior maxilla. It had become noticeable since the last four months and had started interfering with his feeding.
On examination, a 2 x 2 cm swelling arising from the right maxillary alveolar region was seen, which was well-circumscribed, firm, and nontender. It extended to the anterior palate and was large enough to obliterate the nasolabial fold, thus making the lips incompetent at rest. The overlying mucosa was intact and there was no lymphadenopathy [Figure 1]. Considering the patient's age and site of the swelling, the differential diagnosis included developmental odontogenic lesions, for example, adenomatoid odontogenic tumor and eruption cyst, and nonodontogenic entities such as melanotic neuroectodermal tumor of infancy.
The CT scan of the jaw bones was obtained, with and without nonionic contrast, in both the axial and coronal sections, which showed a solitary, intraosseous, ill-defined, homogenous iso- to hypodense mass arising from within the right maxilla. The post-contrast study showed homogenous enhancement, which was mild to moderate. There was evidence of erosion in both cortices, which was smooth in nature [Figure 2] and [Figure 3].
Fine needle aspiration cytology (FNAC) of the lesion was carried out, which was nondiagnostic, and hence a decision was taken to carry out an incisional biopsy under general anesthesia. The biopsy revealed densely packed collagen bundles interspersed with wavy bundles of nerve tissue having spindle nuclei. The fibroblasts were plump and multiple, and spindle shaped fibrocytes were evident [Figure 4]. No dysplastic features were reported in the specimen given. An immunohistochemical test for the S-100 protein was positive (detection system used was the HRP polymer) confirming the neural origin of the tumor. The epithelial membrane antigen (EMA), however, was negative, hence ruling out von Recklinghausen's disease. The histological diagnosis was therefore suggestive of neurofibroma [Figure 5] and [Figure 6].
Under general anesthesia, the lesion was excised in toto sparing the mucosa, and a primary closure was achieved. The tumor was well-encapsulated and could be enucleated easily.
On a one-year follow up, there is no sign of recurrence [Figure 7].
Most solitary neurofibromas in the oral cavity appear in the soft tissues and an intraosseous neurofibroma is a rare entity. An accurate incidence of a solitary intraosseous neurofibroma is difficult to ascertain because of the confusion with neurilemmoma and neurofibromatosis.  Fawcet and Dahlin reported seven such tumors in their review of 3987 primary jaw bone tumors, the most common site being the mandible.  Twenty-nine cases of intraosseous neurofibromas were reported by Polak  in 1989. Intraosseous neurofibroma is rarer still in the maxillae. In our search we could find only seven citations of intraosseous neurofibroma in the maxillae in the last 20 years.
In the cases reported earlier, the average age of presentation of the lesion was 27.5 years with a range of 14 - 45 years. As with neurofibromas presenting in other regions, there does not appear to be any sex predilection. In contrast, our patient was only five months old, probably the youngest reported so far with a solitary intraosseous neurofibroma.
These lesions may be difficult to diagnose initially because of their histological similarity to other fibrous lesions such as juvenile fibromatosis or fibromyxoma. The biopsy should therefore include a representative area of the lesion from the deeper portions of the soft tissue swelling.  Nerve sheath cells of the peripheral nerve consist of Schwann cells, perineurial cells, and endoneurial fibroblasts. These cells exhibit characteristic ultrastructural features and immunophenotypes. The S-100 protein and EMA are known as specific markers to Schwann cells and perineurial cells, respectively. Among the immunohistochemical markers for nerve sheath cells, the S-100 protein was introduced in immunohistochemistry very early and is still a useful marker for Schwann cells. There is proliferation of all the elements of the peripheral nerve - Schwann cells, axons, perineural cells (plexiform type), and fibroblasts, in neurofibromas. Hence, 30 - 40% of the tumor cells are positive to S100 protein. Axons are neurofilament positive. The neurofibroma is immunoreactive to the S-100 protein, [7,8] and this immunological marker was positive in our case.
Epithelial membrane antigen-positive staining for perineural cells is always suggestive of plexiform neurofibroma. Since this EMA was negative in our case, it helped us to rule out von Recklinghausen's disease, in which plexiform neurofibroma is a common finding. S-100 positivity and EMA negativity is therefore suggestive of solitary neurofibroma. 
Although the recurrence rate is low, there have been reports of a malignant transformation of these tumors, with the possibility that the presumed lesion may have been the first manifestation of von Recklinghausen's disease.  Thus a close follow up is warranted.
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