Ameloblastic Carcinoma: A Report of Three Cases

Abstract

Malignant odontogenic tumours are rare and represent approximately 1% of all oral malignancies. Ameloblastic carcinoma is a rare odontogenic tumour, which is aggressive in nature with extensive local bone destruction that has retained the features of ameloblastic differentiation and also exhibits cytological features of malignancy. It occurs primarily in the mandible in a wide range of age groups. It may arise de-novo or in pre-existing ameloblastoma or odontogenic cyst. The purpose of this report is to present three cases of ameloblastic carcinoma with varying presentations as central and peripheral entities.

Keywords: Ameloblastoma; Extraosseous; Intraosseous; Mandible.

[Table/Fig-1]:

a) Clinical picture shows solitary, sessile, ill-defined growth on the lingual gingiva of tooth # 44, 45, 46; b) Intraoral periapical radiograph shows ill-defined radiolucency; c) Occlusal radiograph shows saucerization of alveolar bone; d) Excisional biopsy – gross specimen.

[Table/Fig-2]:

(a&b): Photomicrograph showing ameloblastic epithelial islands arranged in the form of strands and follicles (H&E, 10x & 20x magnification); (c&d): Photomicrograph showing vesicular, hyperchromatic nuclei, increased nuclear cytoplasmic ratio (H&E, 40x magnification).

[Table/Fig-3]:

a) Intraoral picture depicting well-defined solitary proliferative growth; b) OPG depicts multilocular radiolucency involving ramus & body of the mandible; (c&d): CT scan depicting a homogenous mass in the left mandible; e) Excisional biopsy – gross specimen.

[Table/Fig-4]:

a) Hyperproliferative epithelium in plexiform pattern (H&E, 4x magnification); b) Dysplastic features seen in the central cells of the epithelial island such as hyperchromatic nuclei, keratin pearl formation (H&E, 20x magnification); (c&d): Malignant features – vesicular nuclei, increased nuclear cytoplasmic ratio (H&E, 40x magnification).

[Table/Fig-5]:

a) CT scan depicts well defined radiolucency surrounded by sclerotic border; (b-d): 3-Dimensional CT scan depicts the extent of the lesion; e) Biopsy - gross specimen.

[Table/Fig-6]:

(a&b): Epithelial islands arranged in the form of follicles (H&E, 4x & 10x magnification); (c&d): Ameloblastic features: peripheral tall columnar cells with reverse polarization and central stellate reticulum like cells, malignant features :open faced nuclei, Increased mitotic activity, areas of haemorrhage, increased nuclear cytoplasmic ratio and binucleated cells (H&E, 20x & 40x magnification).