A Rare Simultaneous Occurrence of Odontogenic Keratocyst and Unicystic Ameloblastoma in Mandible: A Case Report

Abstract

Odontogenic Keratocyst (OKC) and Ameloblastomas are slow growing benign odontogenic lesions that primarily occur in the molar region of the mandible. Clinically and radiographically both ameloblastoma, especially the Unicystic ameloblastoma and OKC are indistinguishable due to the similar location of occurrence and the age of patients. It is very rare for these lesions to arise simultaneously in a patient's jaw. The co-occurrence of Ameloblastomas with odontogenic cysts or other odontogenic lesions (histologically in a single lesion)have already been described as combined or hybrid lesions. There are very few reported cases in the English literature for simultaneous occurrence of Unicystic Ameloblastoma and OKC as completely distinct lesions. Here we present such a rare case of the simultaneous occurrence of OKC and ameloblastoma in the posterior region of the mandible of a 22-year-old male in close relation.

Keywords: Cystic ameloblastoma; Hybrid lesions; Keratocystic odontogenic tumors; Odontogenic lesions.

[Table/Fig-1a,b]:

Preoperative photographs (a) Frontal view, (b) Worm’s view. Antero-posteriorly swelling extends from left mandibular angle to left mandibular body region, super-inferiorly from the inferior border of the mandible to tragus.

[Table/Fig-2a,b]:

CBCT showing (a) two separate radiolucent lesions in panoramic view, one anterior to lower left third molar, another lesion distal to third molar. (b) Axial and sagittal section showing thinning of buccal and lingual cortical bone. Resorption of roots of the second molar was seen with the downward shifting of the inferior alveolar canal with intact inferior border.

[Table/Fig-3a-e]:

(a) Marsupialized cystic cavity; (b) Povidine-iodine soaked gauze pack kept in situ in marsupialized cavity; (c) Specimen from marsupialized cavity, (d) Enucleated cystic lining; (e) Acrylic denture plate gave for maintaining patency of cystic cavity.

[Table/Fig-4a,b]:

Histopathological analysis of the specimens obtained from the lesions following incisional biopsy; (a) Specimen from the lesion anterior to the third molar revealed a thin layer of regularly parakeratinized stratified squamous epithelium and fibrous connective tissue. The histopathological diagnosis was of the keratocystic odontogenic tumor; (b) Specimen from the lesion distal to the third molar revealed trabeculation of enamel organ-like tissue with proliferation of epithelium into stellate reticulum like cells. Histopathological analysis indicated ameloblastoma. Specimens were stained with hematoxylin-eosin and images were captured at anoriginal magnification of 10X.

[Table/Fig-5a,b]:

Panoramic image (a) before treatment and (b) after 12months of marsupialization. Note significant bone formation around roots of lower left second molar with a reduction in the size of marsupialized lesion and also, a slight reduction in posterior enucleated lesion with mild thickening of the posterior border of irthe ramus. FPD has been given to the patient on the support of lower left second molar and premolar by some private dentist without consulting with the authors, although the bridge is stable and patient is comfortable, without any complaint in chewing.