Poster 1144, Language: German, EnglishHanisch, Marcel / Jaber, M. / Kleinheinz, J.Introduction: The 2005 WHO classification distinguishes four types of ameloblastoma: solid/multicystic, extraosseous/peripheral, unicystic, and desmoplastic. Desmoplastic ameloblastoma is classified as a variant of ameloblastoma, with specific clinical, radiological, and histopathological features. Most tumours occur between the ages of 30 and 60, and there is no gender-specific predilection. There are practically no occurrences of desmoplastic ameloblastomas before the age of 20. In most cases, it is the anterior mandibular region that is affected. Immunohistological, tumour-associated markers such as p63 may be increased in the case of a desmoplastic ameloblastoma. The aim should be an excision involving an appropriate safety distance.
Case study: In May 2016, a 60-year-old male patient was referred with a swelling in the premolar/molar region of the left mandible This had been preceded by an operation to remove tooth 38, carried out by a registered oral surgeon. As the spongiosa in the vicinity of tooth 38 seemed conspicuously "soft" to the surgeon, he prescribed a histopathological examination. This found fibrotic tissue, giant cells, and reactive new bone formation with signs of active remodelling. Any malignant process was expressly ruled out, as was an ameloblastoma. We for our part prescribed three-dimensional imaging using CT, and the finding was a "tumorous infiltration of ramus and corpus mandibulae". Another biopsy, carried out with intubation anesthesia, was interpreted in the histopathological finding as a "moderately differentiated squamous cell carcinoma". There followed the partial resection of the mandible with a joint replacement and neck dissection on one side. The histopathological finding classified the excised material as a "desmoplastic ameloblastoma". This unusual histopathological finding was sent to the DOESAK registry for a second opinion, and the final diagnosis of "sclerosing odontogenic carcinoma" with perineural infiltration was made.
Summary: Sclerosing odontogenic carcinoma might mimic a benign tumor. Thus, an interdisciplinary approach taking into consideration all clinical, radiological, and histopathological features is highly recommended to avoid misdiagnosis and false treatment. The case in question thus underlines the necessity of also taking a critical look at histopathological findings. Wisdom teeth not worth preserving should be removed at an early stage to avoid the consequences mentioned above.
