The Alien Antenna Sign
Abstract
68 Ga-FAPI PET/CT has emerged as a promising molecular imaging modality targeting cancer-associated fibroblasts, rather than tumor cells. We report a novel physiological uptake pattern on 68 Ga-FAPI PET/CT in a 56-year-old woman with newly diagnosed invasive lobular carcinoma of the right breast undergoing staging. 68 Ga-FAPI PET/CT demonstrated intense tracer uptake in the primary right breast tumor and a right level I axillary lymph node, consistent with FAPI expression in the primary malignancy and suspicious nodal involvement. In addition, bilateral linear, rope-like tracer uptake extending from the uterus through the inguinal canals along the round ligaments was observed, creating an "Alien Antenna" appearance. Recognition of this physiological uptake pattern is essential to avoid misinterpretation as peritoneal or metastatic disease.
Fields of Study & Subjects
Peptidase Inhibition and Analysis
Connective tissue disorders research
Bladder and Urothelial Cancer Treatments
Publication details
- Journal / source
- Clinical Nuclear Medicine
- Publisher
- Ovid Technologies (Wolters Kluwer Health)
- Volume
- 51
- Issue
- 9
- Pages
- e834–e835
- Publication date
- 5 May 2026
- Language
- EN