Diagnosis of ectopic adrenocorticotropic hormone (ACTH) and corticotropin releasing hormone (CRH) co-secreting tumors causing Cushing syndrome (CS) is challenging, since these tumors are rare and their diagnosis is frequently confused with Cushing disease (CD), due to the effect of CRH on the pituitary. We report a case of a 21-year-old male who was referred to our institution with persistent hypercortisolemia and CS, after undergoing unnecessary transsphenoidal surgery (TSS). 68Ga-DOTA-TATE-PET/CT revealed increased tracer uptake in the thymus which was postoperatively histologically proven to be a neuroendocrine tumor (NET) that stained positive for ACTH and CRH. Imaging with 18F-FDG-PET/CT was not diagnostic.
Talc pleurodesis (TP) is a technique, widely employed in the management of patients with persistent pleural effusions or pneumothoraces not amenable to other treatment options. It is well documented, that talc deposits produce areas of highly increased 18F-FDG uptake, due to talc-induced inflammation. We present a case of a patient with history of TP who was evaluated with both 18F-FDG and 68Ga-DOTA-TATE. The hypermetabolic area seen on 18F-FDG-PET-CT in the region of talc placement, showed no uptake by 68Ga-DOTA-TATE, suggesting the potential role of 68Ga-DOTA-TATE-PET-CT in elucidating 18F-FDG-postitive lesions in patients with history of both neuroendocrine malignancy and TP.