ODONTOGENIC CYSTS AND TUMORS – A PICTORIAL ESSAY

By

Azian Abd. AzizA Rohaya MudaB, Humairah S.Cheung^A, C.J. VincentC

SUMMARY

We present pictorial illustrations of 12 cases with odontogenic cysts and tumours. The odontogenic cysts consist of 2 cases of inflamed periapical cyst, 2 cases of inflamed dentigerous cyst, 1 case of calcifying odontogenic cyst and 1 case of odontogenic keratocyst. 1 case was reported only as odontogenic cyst (the specific type was not determined). There are 4 cases of ameloblastoma and 1 case of adenomatoid odontogenic tumour. All this cases were pathologically confirmed by surgery. All these lesions were depicted on conventional radiographs (dental radiographs and orthopanthomography) while only 3 cases had computed tomography performed. Comparable to many previous studies, there is no conclusive information seen to allow accurate diagnosis based only on radiological features. The pictorial essay highlights various radiological appearances of such lesions, which can be a reference for radiologists and medical officers, as well as a teaching tool for the medical students.

Keywords

Odontogenic, cyst, tumours, radiological features

INTRODUCTION

Cysts in the mandible and maxilla and dental cysts represent a diverse group of lesions that are easily visualized by radiographic means. A cyst is a pathologic cavity lined by epithelium that also has a fibrous capsule consisting of compressed connective tissue (1). To define the type of cyst, microscopic examination of the cyst lining along with the radiographic findings is necessary.

Cysts present radiologically as unilocular or multilocular lucent areas of various sizes, contours and definitions. Their relationship to a tooth provides important differential diagnostic features (1).

Many studies were conducted to assess and evaluate the usefulness of various imaging modalities in differentiating the types of cystic lesions affecting the mandible and maxilla particularly by computed tomography (2, 3) and magnetic resonance imaging (4). Features seen on conventional radiographs were also reviewed (5). On this basis, pictorial illustrations of such lesions were made and the radiological features were evaluated to determine if they could help determine the correct diagnosis.

METHODOLOGY

Retrospective search of records were performed at dental department, Hospital Tengku Ampuan Afzan, Kuantan for list of patients with the diagnosis related to odontogenic cysts and tumours from year 2000 to 2001. All the clinical notes and radiological examinations were then traced and compiled and the data were reviewed and summarized. The histopathological results were also noted for correlation. The radiological images were captured using digital camera and were transferred to a hard disc for image manipulation mainly for preparation of the poster. Several drafts were made before the finalized poster was printed.

RESULTS

There were 12 cases with odontogenic cysts and tumours detected in Hospital Tengku Ampuan Afzan, Kuantan, Pahang over a period of 18 months (refer table below).

When their radiological examinations were studied, only differential diagnosis could be made which is confirmed by histopathological reports.

CONCLUSION

Radiological features alone were not helpful in differentiating the various types of odontogenic cysts and tumours although it allows differential diagnosis.

Radiological Images

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1. Ameloblastoma

1a

1b

1c

1d

1e

1f

2. Odontogenic Keratocyst

2a

2b

3. Adenomatoid Odontogenic Tumour

4. Inflamed Periapical Cyst

5. Inflamed Dentigerous Cyst

6. Odontogenic Cyst (Specific type not determined)

7. Calcifying Odontogenic Cyst

7a

7b

7c

REFERENCES

1.      Weber A.L. Imaging of cysts and odontogenic tumours of the jaw. Definition and classification. Radiologic Clinics of North America 1993; 31(1): 101-120.

2.      Tozaki M, Hayashi K, Fukuda K. Dynamic multislice helical CT of maxillomandibular lesions: distinction of ameloblastomas from other cystic lesions. Radiat Med 2001; 19(5): 225-30.

3.      Yoshiura K, Higuchi Y, Araki K, Shinohara M, Kawazu T et al. Morphologic analysis of odontogenic cysts with computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997; 83(6): 712-8.

4.      Minami M, Kaneda T, Ozawa K, Yamamoto H, Itai Y et al. Cystic lesions of the maxillomandibular region: MR imaging distinction of odontogenic keratocysts and ameloblastomas from other cysts. Am J Roentgenol 1996; 166(4): 943-9.

5.      Eisenbud L, Kameros J, Blum B, Glass W. The importance of panographic and dental evaluation for lesions of the antrum. Laryngoscope 1976; 86(7): 1004-7.