AMELOBLASTOMA - CYTOLOGIC FINDINGS AND LITERATURE-REVIEW

OBJECTIVE: To define and elaborate the cytomorphologic features of pri mary and metastatic ameloblastoma (ABL) on fine needle aspiration (FNA ) and to discuss the differential diagnosis with closely related entit ies and review the cytologic literature on the subject. STUDY DESIGN: A retrospective study consisting of five cases of ameloblastomas, prim ary in the mandible (n = 3) and metastases (n = 2), diagnosed by FNA c ytology with appropriate cytohistologic correlation, was done. Smears were stained with the Diff-Quik and Papanicolaou methods. Hematoxylin and eosin-stained sections of paraffin block as well as sections from the surgically resected specimens were also reviewed. RESULTS: The sme ars were hypercellular and occasionally showed tissue fragments of bas aloid cells with peripheral palisading. A distinct, two-cell populatio n was seen, consisting of small, hyperchromatic, basaloid-type cells a nd scattered larger cells with more open chromatin. Occasional fragmen ts of mesenchymal cells with more elongated nuclei and ample, clear cy toplasm. were also noted. Malignant cases that metastasized showed pro minent cytologic pleomorphism, cellular crowding with molding and a hi gh mitotic/karyorrhectic index. CONCLUSION: In the right clinical sett ing and with proper radiologic evidence, the cytologic features of pri mary and metastatic ameloblastoma are unique. Diagnostic problems may arise when these lesions are pleomorphic and frankly malignant, especi ally at metastatic sites, such as the lung. FNA, therefore, is a valua ble diagnostic tool in the initial diagnosis and follow-up of patients with a history of ameloblastoma.