A.O. Lawal, A.O. Adisa and M.A Olajide
Department of Oral Pathology, College of Medicine, University of Ibadan, Nigeria..
Abstract
Objective: Cystic ameloblastoma represent 10-15% of all intra osseous ameloblastomas and appear to be less aggressive than the solid ameloblastomas. The aim of this study was to examine the clinico-pathologic characteristics of cystic ameloblastomas seen at a tertiary health care centre.
Materials: All cases diagnosed as cystic ameloblastoma in the Oral Pathology Department of University College Hospital, Ibadan over a 10 year period were investigated for age, gender, location of lesion, treatment, and follow-up. The cases were classified as luminal, intraluminal or mural, based on Ackermann classification. The data was entered into the statistical package for the social sciences version 18 (SPSS 18) and results expressed as percentages.
Results: Fifteen cystic ameloblastomas, representing 14.3% of a total of 105 ameloblastoma cases were seen. The mean age was 28.9(±14.5) years with 73.4% occurring in the second and third decades. The male:female ratio was 2:3. Fourteen (93.3%) of the lesions were in the mandible while only one (6.7%) was in the maxilla. The mural variant was the most common histological variant with 6(40%) cases while the luminal and intra-luminal had 4(26.7%) and 5(33.3%) respectively. The multilocular radiologic appearance was more common than the unilocular in this study (ratio 8:4). Cystic ameloblastoma with multilocular appearance occurred in a higher age group (mean age 31yrs) when compared with the unilocular type which had a mean age of 16.3years.
Conclusion: This study shows similar findings with previous studies but shows a higher multilocular radiological appearance as compared to unilocular variant and no case of recurrence.
Keywords: Cystic ameloblastoma, Clinico-pathologic review, Uni-locular, Multi-locular
Correspondence:
Dr. A.O. Lawal
Department of Oral Pathology,
College of Medicine,
University of Ibadan
Tel: +2348055133964
Fax: +23422411768
E-mail: lawaloluwatoyin@gmail.com
Introduction
Ameloblastoma is the commonest odontogenic tumour in Africans and Asians and arguably the most clinically significant, odontogenic tumour.1 Ameloblastoma is classified clinically into solid, cystic, peripheral, malignant and carcinomatous types.2 The cystic ameloblastoma was first identified by Robinson and Martinez in 1977.3 Unicystic ameloblastoma (UCA) is a more common term used to designate these pathological entities, however, this name became less desirable because they can occasionally present as multilocular radiolucencies. The term ‘cystic ameloblastoma’ is therefore more appropriate.2
Cystic ameloblastomas represent 10-15% of all intra osseous ameloblastomas1 and appear to be less aggressive than the solid ameloblastomas therefore many authors have recommended a less aggressive treatment protocol for this variant of ameloblastoma.
Cystic ameloblastomas is classified into 3 histologic subsets. Group 1(luminal) consists of a cystic lesion lined by simple odontogenic epithelium. The epithelial lining of the lumen is uniform in thickness and has a slightly hyperchromatic layer of palisaded basal cells, most of which exhibit reversed polarization of the nucleus. Group 2 (intra-luminal) consists of a cystic lesion showing intra-luminal proliferation of the epithelial lining. Group 3 (mural) consists of a cystic lesion with epithelial invasion of the supporting connective tissue in either a follicular or plexiform pattern. 4
Although diagnosis of cystic ameloblastoma may connote treatment and prognostic significance, few studies in Nigeria 5 have examined the clinico-pathologic features of cystic ameloblastomas. The aim of this study was to examine the clinico-pathologic characteristics of cystic ameloblastomas seen at a tertiary health centre in Ibadan, Nigeria.
MATERIALS AND METHODS
All histologically diagnosed cases of ameloblastoma over a 10 year period (2001-2010) in the Oral Pathology Department of the University College Hospital Ibadan were reviewed. Out of these, all haematoxylin and eosin stained slides of cases diagnosed as cystic ameloblastoma were reviewed to confirm the initial diagnosis. Case notes were reviewed for age, gender, location of lesion, treatment, and follow-up. Radiographs were also assessed for the radiologic appearance of the lesion (unilocular or multilocular). A diagnosis of cystic ameloblastoma was made when a well-defined single cystic sac lined by odontogenic (ameloblastomatous) epithelium was seen. The histological patterns were then categorized as luminal, intra-luminal or mural based on Ackermann et al classification (1988). The data was entered into the statistical package for the social sciences version 18 (SPSS 18) and results expressed as percentages.