Histological Validation of FDG and PSMA-Targeted PET/CT Imaging in a Rare Tracheal Adenoid Cystic Carcinoma

Abstract

Adenoid cystic carcinomas are the second most common entity of tracheal malignancies, which have an overall incidence as low as only 0.2 in 100,000 persons per year. We present the case of a 64-year-old man with a histologically confirmed adenoid cystic carcinoma who sequentially underwent 18 F-FDG PET/CT and 68 Ga-PSMA-11 PET/CTwithin 1 day for staging 3 days before surgical resection of the tumor. Immunohistochemistry revealed PSMA expression of the tumor corroborating the PSMA PET findings.

Case report: [18F]FAPI-42 PET/CT visualize primary adenoid cystic carcinoma not detected by [18F]FDG

“…In addition, some researchers have reported the application of PSMA imaging in ACC. They found that PSMA can find more metastatic lesions compared with FDG [12,13]. However, the uptake of primary lesions may still be hided due to the widespread expression of PSMA in normal salivary gland epithelium.…”

VEXAS Syndrome With Tracheal Involvement but Absence of Vasculitis in FDG PET/CT

“…3 Differential diagnoses for tracheal cartilage uptake include polychondritis, 10 polyangiitis with granulomatosis, 11 IgG-4-related disease, 12 tuberculosis, 13 postradiogenic necrosis, 14 or malignancies such as lymphoma, 15,16 lung cancer, 17 and adenoid cystic carcinoma. 18,19 In conclusion, owing to the widespread use of FDG PET/CT in the workup of inflammation of unknown origin, nuclear medicine physicians should be aware of possible FDG uptake patterns and commonly involved organs in the only recently established disease VEXAS syndrome. In the future, FDG PET/CT might also be used for monitoring therapy response in VEXAS syndrome.…”