COM February 2007

This is a healthy 15-year-old Caucasian girl who first presented to the University of Washington Pediatric clinic with slight mucosal thickening and swelling in the right hard palate below teeth #s 4 & 5 (Fig 1).  The swelling was asymptomatic and of unknown duration.  It was the same color as the surrounding mucosa and was firm to palpation.  It was smooth-surfaced with defined borders around 2 X 1.5 in length and width.  A small Incisional biopsy was performed at the Oral Surgery clinic, University of Washington.

Figure 1. This is a clinical photograph from when the patient first presented to the Oral Surgery clinic, University of Washington. Note the slight swelling with surface thickening.

Her medical history is not significant for any diseases or allergies.

The patient was first seen at the Pediatric Clinic, University of Washington, School of Dentistry for a swelling in the right hard palate.  The swelling was of unknown duration and was asymptomatic.  The surrounding teeth were vital and the radiographs were negative for any periapical lesions.  The swelling was firm and the same color as the surrounding mucosa (Fig 1).  It was of a significant size around 2 X 1.5 in length and width.

Figure 1. This is a clinical photograph from when the patient first presented to the Oral Surgery clinic, University of Washington. Note the slight swelling with surface thickening.

The Incisional biopsy was diagnosed by Dr. Thomas Morton, University of Washington and the surgical specimen was diagnosed by Dr. Raj Kapur, Seattle Children’s Hospital; Department of Pathology.  The histologic evaluation of the Incisional biopsy revealed a small fragment of oral mucosa with an underlying mass of mesenchymal origin.  This mass was made up clusters, cords and sheets of large cells with granular cytoplasm and small oval to round nuclei (Fig 3).  These cells were positive with S-100 protein marker indicating the neural crest origin (Fig 4).  There was no evidence of atypia.  The cells were haphazardly arranged and were surrounded by collagen bundles (Fig 3).

Figure 3. Low power (x100) H & E histology demonstrating sheets of large cells with granular cytoplasm and small round to oval nuclei.  The tumor cells are surrounded by strands of connective tissue.

Figure 4. Higher power (x200) Immunohistochemistry stain with S-100 protein.  The tumor cells are clearly positive with S-100 protein stain indicating the neural origin of this tumor.