G6ran Anneroth 1, Gunnar Berglund 2, K-E Kahnberg 2
Intraosseous salivary gland tissue of the mandible mimicking a periapical lesion
1Departments of Oral Pathology and 2Oral Surgery, Universities of Ume& and Gothenburg, Sweden
G. Anneroth, G. Berglund, K-E. Kahnberg: lntraosseous safivary gland tissue of the mandible mimicking a periapical lesion. J. Oral Maxillofac. Surg. 1990; 19: 74-75. Abstract. A case of a n u n u s u a l site o f salivary gland tissue is presented. T h e lesion a p p e a r e d as a radiolucency between the apices of the lateral incisor a n d canine in a 57-year-old male p a t i e n t a n d simulated a periapical lesion. The canine was f o u n d vital.
Key words: ectopic salivary gland. Accepted for publication 18 November 1989
A n u n u s u a l case is described in w h i c h salivary gland tissue a p p e a r e d as a periapical radiolucency a r o u n d the left lateral incisor a n d the left cuspid in the lower jaw.
Case report Clinical examination A 57-year-old male patient attended an annual check-up at a public dental health clinic. The patient had no subjective symptoms, but a full-mouth X-ray showed a radiolucency between the apices of the canine and the lateral incisor (Fig. 1A). The cuspid tooth was sensitive to electric pulp stimulation but the lateral incisor did not respond. The pulp chamber of the lateral incisor was obliterated but pain sensation was noted at endodontic treatment. Treatment with calciumhydroxide-paste for 6 months followed by root filling did not decrease the size of the lesion. It was therefore decided to explore the lesion surgically. At surgery the cavity appeared to be located at the lingual aspect of the mandibular body. The soft tissue content of the cavity was adherent to the sublingual salivary gland and had no connection to any of the teeth. Nevertheless, apicectomy was carried out on the lateral incisor and the removed tissue sent for histopathological examination. After fixation in 10% neutral formaldehyde solution the surgical specimen was embedded in paraffin and cut in 5/un-thick sections. The sections were then stained with haematoxylin and eosine and van Gieson. The specimen constituted a normal-appearing salivary gland parenchymal tissue. A fibrous connective tissue capsule was found in the periphery (Fig. 2).
Follow-up Because of incomplete healing, a second surgical exploration was carried out after 10
Fig. 1A. Radiograph showing a radiolucency between the apices of 32 and 33. Fig. lB. Radiograph of 32 showing healing after 2 years. months, which included a retrograde amalgam filling of the root of the lateral incisor (Fig. 1B). Both the lingual and buccal bone plate, were destroyed. The fibrotic scar tissue was removed and histologically examined.
Fig. 2: Histological section of ectopic formation of salivary gland tissue in the mandible. Normal salivary gland tissue can be seen including mucinous and serous acini located in a lobulated parenchymal tissue (P). Salivary ducts and lipid cell aggregates (L) are found.
The second surgical specimen showed fibrous connective tissue that in some areas had the morphological appearance of scar tissue. A few scattered lymphocytes were present. No salivary gland tissue was seen.
lntraosseous salivary gland tissue o f the mandible A radiograph 3 years after the second surgery shows a well demarcated defect with partial bone ingrowth. The size and extent of the defect probably represents fibrous healing as found t0 months after the first surgical exploration.
Discussion Salivary gland inclusions mostly occur in bone cavities located near the angle of the mandible. These cavities have been found to have a remarkably consistent position and radiographic appearance 1,4,5,s,9,t2,13,14,17. The defect has been explained either as an area of resorption o f the mandible through pressure from hyperplastic submandibular salivary gland tissue or as a congenital defect due to entrapment of portions of the submandibular salivary gland during the development of the mandible 3. Salivary gland inclusions in the anterior part o f the mandible have been found in only a few cases, either located in the incisor region or between canine and first premolar 2,7,1t'ls. Salivary gland inclusions have occasionally been found in other parts o f the body; such as skin o f the neck, hypophysis, mastoid bone, tonsillar region, cervical lymph nodes, larynx and middle ear 6,1°'16
The case presented emphasises the importance of a proper differential diagnosis and the need for adequate radiographic follow-up after endodontic treatment.
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G. Anneroth Department of Oral Pathology Umed Univemity S-901 87 Ume& Sweden