Melanotic Neuroectodermal tumor of infancy: Case report

A. Al-Bassam, MBBS, FRCS (Ed)*, A. Al-Rabeah, MBBS, MSc, FRCS (C)*
H.A. El-Abdin, BDS, FDSRCPS**
*King Khalid University Hospital,P.O. Box 22226, Riyadh,KSA,
** College of Denstistry, King Saud University, P.O. Box 60169, Riyadh, KSA.

 
Melanotic neuroectodermal tumor of infancy is a rare benign tumor that commonly affects the maxilla. This case is a report on a 4-month-old female infant with melanotic neuroectodermal tumor of the right maxilla. The tumor was successfully excised with no evidence of recurrence at 12 months follow-up. Early wide excision of the tumor to minimize tissue destruction by tumor growth and careful follow-up is recommended.

 
Melanotic neuroectodermal tumor of infancy is considered as a rare tumor. Almost 95% of this tumor is found in infants less than one year of age and is equally distributed in both sexes. The most common site is the maxilla comprising 68.8% with the incisal area being the most frequently involved area.1 Nevertheless, cases in different sites have been reported. The lesion is usually considered benign. Malignancy rate is approximately 1.9 -3.2%.2 Conservative excision is usually adopted but 10 - 15% of this tumor recur locally and may lead to death if it invades local vital tissues.2
Melanotic neuroectodermal tumor (MNT) was first described by Krompecher in 1981. Since that time, more than 100 cases have been reported, under a variety of names that includes melanotic prognoma, pigmented ameloblastoma, pigmented congenital epulis,  pigmented teratoma, atypical melanoblastoma,   congenital   melanocarcinoma, and melanotic epithelial odontoma.
Case Report:
In this report, a 4-month-old Saudi female infant was referred to the Department of Pediatric Surgery, King Khalid University Hospital from a district hospital with a history of swelling in the right upper gum and maxillary region of two months duration but no associated symptoms.
The infant was a product of normal pregnancy and delivery. On examination, the child was healthy-looking and vital signs were stable with no lymphadenopathy. Chest, heart, and abdominal examinations were normal. However, examination of the lesion revealed a swelling in the anterior region of the right upper gum. The lesion was 3x4 cm in diameter, hard in consistency and obliterating the canine fossa on the right side. It was deviating and blocking the right nostril. There was no invasion of the soft and hard palate [Fig, 1 ].
Hemogram, serum electrolytes, renal and liver profiles were normal. Urinary Vanillylmandeiic Acid (VMA) was normal. CT scan of the skull and face revealed a tumor invading the bone of the right maxilla and deviating the nasal septum [Fig. 2].
The child had a biopsy taken from the tumor site which was reported to be a pigmented neuroec­ todermal tumor of infancy. The child has under-gone surgical excision of the tumor. The tumor was enucleated and removed with the bone of the right premaxilla as well as the deciduous teeth. The area extending from the canine fossa to the infra-orbital margin was explored. The bone was shaved and smoothened down with an osteotome and the surgical specimen was sent to the pathology laboratory. The histopathology result confirmed a benign neuroectodermal tumor of infancy [Fig. 3a], The bone proved to be reactive calcification initiated by the presence of the tumor in the area3,4 [Fig. 3b]. Postoperative course was uneventful. A regular follow-up examination for 12 months revealed no evidence of recurrent tumor and the child appeared healthy [Fig. 4].

 
Cutler2 published an extensive review of the literature since the first case report of MNT by Krompecher3 in 1918. The review showed that MNT is a tumor of childhood and the majority of patients were below the age of one year. Nevertheless, adult cases have been reported.2 The majority of cases were benign in nature and commonly located in the maxilla. However, other locations have been reported. The lesion is a fast growing swelling of the incisor region of the maxilla with brown pigmentation commonly seen on the overlying soft tissues. The origin of this tumor is not well known. However, ultra structural studies,2,4 histochemical studies,5 and elevated VMA6 suggested neural crest origin.
Our patient was below six months of age, female, and had right maxillary tumor which proved to be benign in nature clinically and his-topathologically and similar to others reported. Wide surgical excision with removal of some of the tooth buds to avoid local recurrence was performed in our patient as has been reported in the literature.4 Some authors advocated conservative excision and attributed the success of this procedure to the debunking effect and initiation of bodily defense that resulted in destruction of any residual cell of the tumor left behind.7,9 However, the growth rate of the recurrent lesion mass may change from what is initially a simple localized tumor into a more invasive one that causes extensive destruction to healthy tissues. The use of CT scan has been helpful in assessing the extent of the disease and  insured a careful excision without interfering with important structures in the area like the infra-orbital nerve, the orbit, or nasal floor.
This case report stresses the fact that wide local excision is needed to avoid local recurrence which is associated with such tumor. Careful follow up is required in such patients to detect any early recurrence.