Ameloblastoma of the Mandible
Updated: Mar 12, 2021
Enlarging Left Mandibular Mass • Xray of the Week
A 30 year old female presented with rapidly increasing left mandibular swelling over the last 3 months. What is the diagnosis?
Figure.1 (A) Plain radiograph of the mandible showing typical soap-bubble lesion on the left side. (B) CT 3D reconstruction shows multiple osteolytic lesions.
Figure 2. (A) Plain radiograph of the mandible showing typical soap-bubble lesion on the left side. There is breach of the cortex (yellow arrow). (B) CT 3D reconstruction shows multiple osteolytic lesions. There is breach of the cortex (green arrows).
Figure 3. Coronal contrast enhanced CT scan demonstrates intramandibular, expansile lytic lesion with breach of the cortex at multiple sites (yellow arrows). MRI STIR coronal image shows hyperintense, multiloculated, lesion in left side of the mandible (green arrows).
An expansile radiolucent lesion with no calcified matrix in plain x-rays of the jaw suggests many diagnoses, such as odontogenic cysts, nonodontogenic cysts, cystic neoplasms, and inflammatory granulomas. Among them, odontogenic keratocysts, which contain keratinaceous material, and ameloblastomas, which are benign cystic neoplasms have high recurrence rates.
Ameloblastoma arises from the enamel-forming cells of the odontogenic epithelium. The tumor most commonly occurs in the posterior mandible, typically in the third molar region. On radiography, the mixed cystic and solid type of ameloblastoma appears as an expansile, radiolucent, multilocular mass, with internal septations that form a honeycomb or soap bubble appearance on all modalities, which is a classic finding.
References: 1. Minami M, Kaneda T, Ozawa K et-al. Cystic lesions of the maxillomandibular region: MR imaging distinction of odontogenic keratocysts and ameloblastomas from other cysts. AJR Am J Roentgenol. 1996;166 (4): 943-9.
2. Minami M, Kaneda T, Yamamoto H et-al. Ameloblastoma in the maxillomandibular region: MR imaging. Radiology. 1992;184 (2): 389-393.
3. Dunfee BL, Sakai O, Pistey R et-al. Radiologic and pathologic characteristics of benign and malignant lesions of the mandible. Radiographics. 26 (6): 1751-1768.
4. Dunn JL, Olan WJ, Bank WO, et-al. Giant ameloblastoma: radiologic diagnosis and treatment. Radiographics. 1997;17 (2): 531-536.
5. Plunk MR, Oda D, Parnell SE, et-al. Focal Benign Disorders of the Pediatric Mandible With Radiologic-Histopathologic Correlation: Mandibular Development and Lucent Lesions. American Journal of Roentgenology. 2017;208: 180-192.5.
G. Balachandran, MBBS, MD
Dept. of Radiology, Sri Manakula Vinayakar Medical
College and Hospital, Pondicherry, India
Dr. Balachandran is a Professor of Radiology at Sri Manakula Vinayagar Medical College and Hospital (SMVMCH). He earned his MBBS degree at the Government Stanley Medical College in Madras India in 1975, followed by DMRD at the Government Madras Medical College in Madras India in 1984, MD (RD) at Jimper Pondicherry in 1988, and DNB(RD) at MHFW, GO in New Delhi in 1991. Dr. Balachandran is a life member of the Indian Radiological and Imaging Association (IRIA) and the Indian College of Radiology (ICR).