COM September 2005

This is a 12-year-old African American girl who presented to the Seattle’s Children’s Hospital with a history of “jaw bumps” that have been present for an unknown period of time. They have increased in size over the last year and are now of concern esthetically. Lack of past medical attention makes her medical and family histories difficult to assess; the patient is one of six sisters raised by their grandmother. The patient otherwise appears healthy. The clinical examination revealed a 4 cm bony hard lesion on the left angle of the mandible (Fig 1). A similar but smaller lesion is on the right angle of the mandible (Fig 1) and a third is present in the right maxilla. In addition, three soft tissue nodules were identified outside the oral cavity; the largest is 5 cm in size and is on the right parietal scalp region, the second is on the right posterior neck and the third is on the right lateral ankle. The latter two are 2 cm each. The patient was referred to a gastroenterologist and geneticist to confirm the provisional clinical diagnosis.

Figure 1. Panoramic film demonstrating a combination of multiple radiopaque lesions (exophytic and flat), odontoma, retained deciduous teeth and impacted permanent teeth.

The patient’s five sisters display some physical problems that are not clearly defined. Her parents are not available for testing. The patient’s individual history is lacking because her grandmother acts as a single parent for all six children, making regular visits to physicians difficult.

The dentition is mixed consistent with the age of the patient. Both jaws show multiple radiopaque lesions (Fig 1-2) and three skin soft tissue nodules. Three exophytic radiopaque lesions are present bilaterally on each angle of the mandible and right posterior maxilla (Fig 1-2). The mandibular lesions are protruding by approximately 3 cm on the left side and 2 cm on the right side. Both jaws have additional non-expansile radiopaque lesions, including one in the area of tooth #6 which is more consistent with an odontoma. Other non-expansile radiopaque lesions are present in the areas of teeth #s 15-16, 18-19, and 27-29. Five retained deciduous teeth were identified #s A, B, C, H, and K. A badly carious tooth #3 was also identified.

Figure 1. Panoramic film demonstrating a combination of multiple radiopaque lesions (exophytic and flat), odontoma, retained deciduous teeth and impacted permanent teeth.

Figure 2. Anterior posterior skull film demonstrating multiple radiopaque lesions.

Three biopsies were performed: the bony nodules at the angle of the mandible and maxilla, the radiopaque mass in area of tooth #6 and the large soft tissue lesion on the scalp. The bony nodules were made up of dense lamellar bone with Haversian systems with viable osteocytes (Fig 3) consistent with osteomas. The radiopaque mass in the area of tooth #6 was made up of tooth-like structures and dental follicle (Fig 4) consistent with an odontoma while the soft tissue lesion was made up of a cystic structure filled with keratin and surrounded by a thin connective tissue wall (Fig 5) consistent with an epidermal cyst. Although the other two soft tissue lesions (on the neck and ankle) were not biopsied; they were rendered clinically to be consistent with epidermal cysts similar to that of the scalp. The patient is referred to a gastroenterologist for identification of polyps in the colon. Genetic studies will also be performed to establish a definitive diagnosis of Gardner’s syndrome.

Figure 3. Low power (x100) histology shows a large mass of lamellar bone with Haversian systems and viable osteocytes consistent with osteoma.

Figure 4. Low power (x40) histology shows tooth like structures and dental follicle consistent with an odontoma

Figure 5. Low power (x40) histology shows a cystic structure filled with keratin consistent with an epidermal cyst.