The intraoral lesion appeared as a 2 cm sessile, bluish mass located in the left anterior maxillary process. Palpation of the lesion did not seem to cause the infant any discomfort. A slight spongy feeling was suggestive of an absence of the buccal cortex. No thrill or pulse could be elicited from the mass. Although the lesion had supposedly expanded rapidly, the overlying mucosa was intact. (Figure 1)
Figure 1. Intraoral examination reveals a 2 cm elevated bluish mass on the maxillary alveolar ridge.
Under sedation, advanced imaging, using computed tomography (CT), was performed. The axial CT scan revealed a 2 cm radiolucent lesion with irregular borders. The space-occupying lesion was causing the displacement of teeth and interrupting their normal development. (Figure 2)
Figure 2. Axial CT scan reveals a 2 cm ill-defined radiolucency indicating evidence of the destruction of bone and displacement of the developing teeth.
Histopathologic examination revealed a nonencapsulated tumor showing local infiltration into the adjacent bone. The lesion showed a mixture of large polygonal cells and small hyperchromatic round cells which were arranged in sheets or alveolar structures. (Figure 3) A number of the larger cells contained melanin pigment. (Figure 4)
Figure 3. Low-power photomicrograph of the tumor showing infiltrating islands of tumor cells.
Figure 4. High-power photomicrograph of the tumor showing central round hyperchromatic cells surrounded by larger polygonal cells containing brown melanin pigment.
The histopathologic appearance of the specimen led the clinician to order a urinalysis. These results were normal for a young child, except for significantly elevated levels of vanillylmandelic acid (VMA). The VMA value was 3 standard deviations from the mean for a child in this age group.