A Nonulcerated, Slowly Growing Mass of the Mandible
DIAGNOSTIC INFORMATION

History of Present Illness

The patient reported that the lesion had been enlarging slowly for the past 21 years. The mass was not tender and the patient did not recall any history of trauma. No other information was available.

Medical History

The patient’s medical history was unremarkable. He denied alcohol and tobacco use.

Clinical Findings

The clinical exam revealed a 3×2 cm “bony hard” swelling of the right mandible buccal to #27 and #28. The overlying mucosa was intact and no lingual extension was noted (Figure 1). The remainder of the oral cavity was within normal limits.

firm, nonulcerated mass of the right mandibular gingiva
Figure 1. Firm, nonulcerated mass of the right mandibular gingiva.

Radiographic Findings

The periapical radiograph demonstrated a well-defined mixed radiolucent/radiopaque lesion that caused divergence of the roots without resorption. An occlusal radiograph also revealed buccal expansion and scattered opacifications (Figures 2 and 3).

mixed radiolucent/radiopaque lesion
Figure 2. Periapical radiograph demonstrating a mixed radiolucent/radiopaque lesion between teeth numbers 28 and 29.
mixed radiolucent/radiopaque lesion
Figure 3. Mandibular occlusal radiograph demonstrating the mixed radiolucent/radiopaque nature of this lesion.

Biopsy Findings

On microscopic examination, the multiple sections examined revealed islands, strands, and sheets of polyhedral epithelial cells containing mildly pleomorphic nuclei set in a deeply eosinophilic cytoplasm (Figures 4-6).

incisional biopsy specimen
Figure 4. Low power photomicrograph of the incisional biopsy specimen.
areas of epithelial cells admixed with deposits of amorphous material
Figure 5. Medium power photomicrograph demonstrating areas of epithelial cells admixed with deposits of amorphous material.
lamellar calcification
Figure 6. Medium power photomicrograph demonstrating a lamellar calcification.
Hyalinized, eosinophilic amorphous material was noted throughout the stroma. Basophilic calcifications composed of concentric rings also were identified (Liesegang rings). The lesion also demonstrated positive staining with Congo Red and apple/green birefringence under polarized light, a staining pattern consistent with amyloid (Figures 7 and 8).
positive staining with Congo Red
Figure 7. Low power photomicrograph demonstrating positive staining with Congo Red.
Congo Red stain with polarized light showing apple/green birefringence
Figure 8. Congo Red stain with polarized light showing apple/green birefringence.