A 50-year-old woman presented with back pain for 1 month. Chest CT showed osteolytic destruction of T6 vertebral body. A malignancy was suspected. The patient was subsequently enrolled in the clinical trial of 68 Ga-FAPI PET/CT. 68 Ga-FAPI PET/CT revealed multiple bone destruction with increased FAPI activity. It was also highly suggestive of malignancy or metastases. However, pathological examination after T6 vertebral surgery confirmed the diagnosis of tuberculous granulomatous inflammation.

We describe the case of a 48-year-old man suspected to have recurrent colon carcinoma who underwent 68Ga-DOTA-FAPI-04 PET/CT, revealing the presence of an incidentaloma with intense FAPI uptake in the left thyroid lobe. Based on PET/CT findings, malignancy was suspected. Biopsy confirmed the diagnosis of follicular thyroid adenoma with fibrosis and calcification. This case emphasizes the need to increase awareness of this benign lesion in the differential diagnosis of incidental thyroid nodules with high FAPI activity.

A 40-year-old man presented with abdominal pain and diarrhea for 2 months. Abdominal CT showed thickening of the cecal wall, which was considered likely malignant. The patient was subsequently enrolled in a clinical trial of 68 Ga-FAPI PET/CT study in tumors. Intense 68 Ga-FAPI activity was noted in the thickened cecum, also suggestive of malignancy. However, pathological examination from biopsy rendered a diagnosis of chronic colitis.

A 69-year-old man presented with dysphagia for 6 months. Endoscopic biopsy showed no sign of malignancy, but enhanced chest CT revealed thickening of the esophageal wall, which was considered likely a potential malignancy. The patient subsequently was enrolled in our clinical trial of 68 Ga-FAPI study in tumors. Intense 68 Ga-FAPI activity was noted in the thickened esophagus. However, repeated endoscopic biopsies and relief of symptoms after drug treatment rendered a diagnosis of Candida albicans esophagitis.