title: Ameloblastic Carcinoma.
abstract: BACKGROUND
  Ameloblastic carcinoma secondary type is an extremely rare and aggressive odontogenic neoplasm that exhibits histological features of malignancy in primary and metastatic sites. It arises through carcinomatous de-differentiation of a pre-existing ameloblastoma or odontogenic cyst, typically following repeated treatments and recurrences of the benign precursor neoplasm. Identification of an ameloblastic carcinoma, secondary type presenting with histologic features of malignant transformation from an earlier untreated benign lesion remains a rarity. Herein, we report 1 such case.
  
  
  METHODS
  A 66-year-old man was referred for management of a newly diagnosed ameloblastic carcinoma. He underwent radical surgical intervention comprising hemimandibulectomy, supraomohyoid neck dissection, and free-flap reconstruction. Final histologic analysis demonstrated features suggestive of carcinomatous de-differentiation for a consensus diagnosis of ameloblastic carcinoma, secondary type (de-differentiated) intraosseous.
  
  
  CONCLUSIONS
  Ameloblastic carcinoma, secondary type represents a rare and challenging histologic diagnosis. Radical surgical resection with adequate hard and soft tissue margins is essential for curative management of localized disease.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Westmead Hospital, Sydney, Australia.
authors.forename: Dakshika Abeydeera
authors.initials: DA
authors.lastname: Gunaratne
authors.affiliation: Department of Tissue Pathology and Diagnostic Oncology, Pathology West - ICPMR, Westmead Hospital, Sydney, Australia.
authors.forename: Hedley G
authors.initials: HG
authors.lastname: Coleman
authors.affiliation: Department of Oral and Maxillofacial Surgery, Westmead Hospital, Sydney, Australia.
authors.forename: Lydia
authors.initials: L
authors.lastname: Lim
authors.affiliation: Department of Surgical Oncology, Head and Neck Surgery, Westmead Hospital, Sydney, Australia.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Morgan
mesh_terms: D000368:Aged; D000564:Ameloblastoma / Q000175:diagnosis* / Q000556:secondary; D001706:Biopsy; D003937:Diagnosis, Differential; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008339:Mandibular Neoplasms / Q000175:diagnosis*; D063168:Mandibular Osteotomy / Q000379:methods*; D037981:Neck Dissection; D011862:Radiography, Panoramic