Diagnostic Information

History of Present Illness Larry is 49 year-old male who presented for his 6 month dental recall examination. He was doing well and had no dental complaints. Periodontal evaluation revealed a 10 mm probing depth on the distal of tooth #2. The probing depths in this area 6 months earlier were 3 to 4 mm. A radiograph revealed a distal periradicular and apical radiolucency involving tooth #2. Tooth #2 did not respond to vitality testing and a diagnosis of a combined endodontic/periodontic lesion was established. Nonsurgical endodontic therapy and scaling and root planing were completed. A follow-up radiograph in 3 months showed no evidence of healing of the defect and the presence of a new periapical lesion around tooth #3 (Figure 1). Nonsurgical endodontic therapy was then completed on tooth #3. The patient remained asymptomatic but radiographic expansion of the lesion was noted at a three month follow-up exam (Figure 2). No cortical expansion, fistula tract, or drainage was noted. Moderate tooth mobility was present. Teeth #2 and #3 were then extracted a a fleshy tan-white tissue was curetted from the extraction sites and submitted for histologic examination. Medical History - Adverse drug effects: none

- Medications: fosinopril, albuterol inhaler, aspirin, fish oil, daily vitamins

- Pertinent medical history: hypertension, mild chronic obstructive pulmonary disease

- Pertinent family history: paternal - type II diabetes, hypercholesterolemia, myocardial infarction; maternal - rheumatoid arthritis

- Social history: 25 pack/year history of cigarette smoking; social alcohol use (mixed drinks); denies recreational drug exposure Clinical Findings The periapical radiographs of the right posterior maxilla show an enlarging destructive radiolucent lesion involving the roots of teeth #2 and #3 (Figures 1 and 2).

Figure 1. Three month follow-up radiograph following completion of endodontic therapy on tooth #2 showing persistence of the periradicular radiolucency associated with tooth #2 and development of a new periapical radiolucency on tooth #3.

Figure 2. Three month follow-up radiograph following completion of endodontic therapy on tooth #3 showing an enlarging radiolucent lesion of the right posterior maxilla.

Histopathologic Findings The histologic sections of the biopsy showed an infiltrate composed predominantly of histiocytes with interspersed eosinophils, lymphocytes and rare plasma cells (Figure 3). The histiocytes display bean shaped indented/grooved nuclei and abundant pink cytoplasm. Occasional multinucleated giant cell were present (Figure 4). Immunohistochemical stains showed the histiocytes to be positive for CD1a (Figure 5) and CD207 (Figure 6).

Figure 3. Low power histologic image showing a diffuse infiltrate of histiocytes with admixed eosinophils.

Figure 4. High power histologic image showing histiocytes with grooved vesicular nuclei and abundant pink cytoplasm. Eosinophils and focal multinucleated giant cells are present in the background.

Figure 5. Immunohistochemical stain for CD1a showing positive membrane staining of the histiocytes.

Figure 6. Immunohistochemical stain for CD207 showing positive cytoplasmic staining of the histiocytes.