ABSTRACT
AIM: Staging of head and neck tumors is one of the most difficult tasks in imaging techniques, due to the very complicated head and neck anatomy and serious problems with the differentiation of reactive enlarged lymph nodes and lymph nodes involved with metastases. The aim of the study was to evaluate the validity of the whole-body approach in the assessment of head and neck malignancies using (18)F-FDG-PET/CT. MATERIALS AND METHODS: The analysis of a group of 1750 consecutive whole-body procedures in all indications of (18)F-FDG-PET/CT was made according to: the presence of orofacial tumors; their histology; findings concerning the spread outside head and neck region; and findings concerning the primary staging or restaging. The examinations of head and neck tumors were performed after intravenous application of the (18)F-FDG and its accumulation for one hour. Drinking and speaking is restricted during this accumulation to prevent artificial muscle (18)F-FDG uptake and to minimize false positive findings. In our hospital, high resolution PET is followed by the sub-millimeter isotropic acquisition of CT data after intravenous application of an iodinated contrast material. The acquisitions of head and neck region and trunk are performed separately to obtain optimal resolution in both regions. RESULTS: 105 examinations of the orofacial tumors were performed on 87 patients in a group of 1750 consecutive PET/CT examinations. The ratio between primary staging and restaging was 3:7. The most frequent indications were carcinomas of the tongue (19 examinations) and carcinomas of the salivary glands (19 examinations). The metastatic spread of the tumor outside the region of the head and neck was noted in 12 cases. CONCLUSION: Our findings of distant metastases confirmed the importance of the use of whole-body PET/CT in this indication.
Subject(s)
Fluorodeoxyglucose F18 , Head and Neck Neoplasms/diagnosis , Positron-Emission Tomography/methods , Subtraction Technique , Tomography, X-Ray Computed/methods , Whole Body Imaging/methods , Female , Humans , Male , Radiopharmaceuticals , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
High-grade transformation of acinic cell carcinoma (AciCC) (previously referred to as dedifferentiation) is a rare phenomenon characterized by histologic progression of low-grade AciCC to high-grade adenocarcinoma or undifferentiated carcinoma. We report 9 new cases with immunohistochemical analysis and examination of HER-2/neu and p53 genes to further define the profile of this tumor. Histologically, the high-grade component was composed of polymorphic cells with a high mitotic rate arranged in glandular and solid growth patterns with comedonecrosis. The MIB-1 labeling indices were elevated in the high-grade component, as compared with the low grade conventional AciCC. The high-grade component of AciCC was characterized by strong membrane staining for CK18 and beta-catenin, and nuclear staining for cyclin-D1. HER-2/neu, androgen receptor, C-kit, and epidermal growth factor receptor were absent from both low-grade and high-grade components. In contrast, S-100 protein, alpha-1-antitrypsin, and lysozyme were lost only in high-grade foci of transformed AciCC. The median age was 61 years (with range from 43 to 76 y). Lymph node (LN) metastases were found in 5 of 9 cases (56%). Distant metastases to the lungs (n=4), pleura (n=2), brain (n=3), and peritoneum (n=1), and paraaortic, paratracheal, and mediastinal LNs (n=2) were observed. Six of 9 patients (66%) died from tumor dissemination, all with a median overall survival of 4.3 years (range: 1 to 9 y). The high propensity for LN metastases indicates the need for neck dissection at the time of diagnosis.
