Spindle cell variant of ameloblastic carcinoma: A diagnostic challenge

An 18-year-old male presented with a 3-week history of progressively enlarging nodular growth in the posterior right mandibular region. The patient denied the use of tobacco in any form or history of trauma, and his family history was unremarkable. Clinical examination revealed a 2 × 3 cm reddish-pink, firm lesion with palpable submandibular lymph nodes. Radiological imaging showed a well-defined radiolucency distal to tooth #47. An incisional biopsy revealed the proliferation of spindle cells and ameloblastomatous epithelium showing features like pleomorphism, cellular crowding, and mitotic figures. Immunohistochemical analysis confirmed odontogenic origin. Based on the above findings, the diagnosis of the spindle cell variant of ameloblastic carcinoma (AC) was rendered. AC, constituting less than 2% of odontogenic tumours, and the spindle cell variant, a rare subtype with fewer than 15 reported cases, pose diagnostic challenges, necessitating careful histopathological and immunohistochemical evaluation for accurate diagnosis and treatment planning.