Pulmonary Lymphangitis Carcinomatosis in Rapid Progressive Recurrent Pheochromocytoma: A Case Exhibiting the Peer Diagnostic Value of 99mTc-FAPI-46 and 99mTc-HYNIC-Octreotide Scans.

A 43-year-old woman with a history of left adrenal pheochromocytoma was suspected for recurrence 2 months after adrenalectomy. Imaging assessments revealed metastatic lesions in the lungs and abdominal lymph nodes. Despite initial treatment with long-acting octreotide, the patient's symptoms worsened. Consequently, the patient was referred to the nuclear medicine department for theragnostic purposes. Comprehensive re-evaluation revealed a recurrent tumor in the left adrenal bed and multiple metastatic lesions, including lung, liver, lymph nodes, and skeletal metastases. In this patient, 99mTc-FAPI-46 scintigraphy demonstrated similar imaging capabilities compared with 99mTc-HYNIC-Octreotide scan, highlighting its potential in metastatic pheochromocytoma imaging and therapy.