FDG-PET/CT of invasive thymoma extending into the superior vena cava and right atrium.

We present FDG PET/CT findings of a rare case of invasive thymoma with intraluminal growth into the superior vena cava (SVC) and right atrium (RA).

18F-FDG PET/CT and Contrast-Enhanced CT of Primary Malignant Tracheal Tumor.

PURPOSE: Primary malignant tracheal tumors are rare, and their clinical presentation often resembles other diseases of the respiratory system. This study summarized F-FDG PET/CT and CE-CT findings on histologically confirmed primary malignant tracheal tumors in 13 patients. MATERIALS AND METHODS: We retrospectively reviewed the F-FDG PET/CT and CE-CT findings of 13 patients with histologically confirmed primary tumors who had undergone PET/CT and CE-CT in the same session. The following parameters were recorded: SUVmax; SUVmax lesion/background; location, size and attenuation of the mass; mediastinal invasion; and the presence of metastases. Clinical data, bronchial endoscopy results, and surgical and histopathological findings were also collected. RESULTS: Tracheal soft tissue lesions with increased F-FDG uptake were observed in all patients. Five squamous cell carcinomas, 5 adenoid cystic carcinomas, 2 adenocarcinomas, and 1 mucosa-associated lymphoid tumor were histopathologically observed. The maximum SUV of the malignant tracheal tumors ranged from 2.7 to 20.5 (mean ± SD, 6.8 ± 4.8; median, 5.7). All SUVmax lesion values were greater than 2.5. Homogeneous enhancement was observed in all lesions, with three exhibiting evident enhancement, nine demonstrating moderate enhancement, and one showing mild enhancement. CONCLUSIONS: The presence of a tracheal soft tissue mass with increased F-FDG uptake is highly suggestive of a malignant tracheal tumor. F-FDG PET/CT and CE-CT can clearly demonstrate such a tumor's function and anatomical characteristics.