Intracranial Ameloblastoma Arising from the Maxilla: An Interdisciplinary Surgical Approach.

Background Ameloblastomas are a rare tumor entity accounting for only 10% of all odontogenic tumors. They mostly originate from the mandible. Only a few cases are known to grow aggressively and to invade the orbit, nasal cavity, or even the brain. Patient and Methods/Case Report We present the case of a 57-year-old patient who was admitted with a huge tumor involving the nasal cavity, the left maxilla, and the anterior fossa. Histologic diagnosis was made by biopsy. A combined two-stage neurosurgical maxillofacial approach was planned. First the intracranial tumor mass was removed using bifrontal trepanation. A duraplasty was sewn in to cover the brain. In the second procedure, a combined bifrontal and midfacial approach was used by craniofacial plastic surgeons and neurosurgeons. A perisinusoidal tumor mass and retropharyngeal tumor mass was removed up to the skull base. The left orbit was completely exenterated, and a fibular bone-muscle graft was used for palatal, orbital, and facial reconstruction. The facial vein and artery were carefully prepared to feed the bone-muscle graft by end-to-end anastomoses. Conclusion Ameloblastomas are very rare slow-growing tumors that show a tendency to recur. They are responsible for only 1% of all oral tumors. Their growth can be enormous, and they can extend into sinusoidal cavities, the orbit, and the brain. Complex and extensive palliative surgery can ease the concerns of these patients and prolong their survival.

Objective and subjective image quality of primary and recurrent squamous cell carcinoma on head and neck low-tube-voltage 80-kVp computed tomography.

INTRODUCTION: To investigate low-tube-voltage 80-kVp computed tomography (CT) of head and neck primary and recurrent squamous cell carcinoma (SCC) regarding objective and subjective image quality. METHODS: We retrospectively evaluated 65 patients (47 male, 18 female; mean age: 62.1 years) who underwent head and neck dual-energy CT (DECT) due to biopsy-proven primary (n = 50) or recurrent (n = 15) SCC. Eighty peak kilovoltage and standard blended 120-kVp images were compared. Attenuation and noise of malignancy and various soft tissue structures were measured. Tumor signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective image quality was rated by three reviewers using 5-point grading scales regarding overall image quality, lesion delineation, image sharpness, and image noise. Radiation dose was assessed as CT dose index volume (CTDIvol). Interobserver agreement was calculated using intraclass correlation coefficient (ICC). RESULTS: Mean tumor attenuation (153.8 Hounsfield unit (HU) vs. 97.1 HU), SNR (10.7 vs. 8.3), CNR (8.1 vs. 4.8), and subjective tumor delineation (score, 4.46 vs. 4.13) were significantly increased (all P < 0.001) with 80-kVp acquisition compared to standard blended 120-kVp images. Noise of all measured structures was increased in 80-kVp acquisition (P < 0.001). Overall interobserver agreement was good (ICC, 0.86; 95 % confidence intervals: 0.82-0.89). CTDIvol was reduced by 48.7 % with 80-kVp acquisition compared to standard DECT (4.85 ± 0.51 vs. 9.94 ± 0.81 mGy cm, P < 0.001). CONCLUSIONS: Head and neck CT with low-tube-voltage 80-kVp acquisition provides increased tumor delineation, SNR, and CNR for CT imaging of primary and recurrent SCC compared to standard 120-kVp acquisition with an accompanying significant reduction of radiation exposure.