False-Positive Rate of Positron Emission Tomography/Computed Tomography for Presumed Solitary Metastatic Adrenal Disease in Patients with Known Malignancy

Abstract

The 20 % false-positive rate for PET-positive adrenalectomies performed for metastatic disease should warrant its inclusion in preoperative counseling to the patient and interaction with the treating oncologist.

High False Positivity in Positron Emission Tomography is a Potential Diagnostic Pitfall in Patients with Suspected Adrenal Metastasis

“…Even if one excluded the non-functional pheochromocytoma (as this is a heterogeneous tumor with malignant potential), the false positive rate was still 10/38 or 26.3%. This false positive rate appeared even higher than that of a recent study that examined the accuracy of FDG-PET/CT based on histology 9 .…”

“…Even if one excluded the non‐functional pheochromocytoma (as this is a heterogeneous tumor with malignant potential), the false‐positive rate was still 10/38 or 26.3 %. This false‐positive rate appeared even higher than that of a recent study that examined the accuracy of FDG‐PET/CT based on histology [9]. Interestingly, when one looked at the chance of adrenal metastasis among the four clinical suspicion categories, the false‐positive rate for FDG‐PET/CT was actually higher than having either a new adrenal lesion or an adrenal lesion with interval enlargement or “indeterminate” CT features (28.2 vs 25.0 %, 26.7 %, 20.0 %, respectively).…”

“…However, it is not perfect because although most benign adenomas have FDG uptake equal to or below liver (i.e., appearing as little to no uptake), some exhibit FDG uptake greater than the liver (i.e., increased uptake), therefore mimicking metastases. In fact, a recent study has found an unexpected high false-positive rate (i.e., an adrenal lesion appearing positive on FDG-PET/CT but ending up benign on histology) [9]. Given that the vast majority of the current literature reporting the accuracy of FDG-PET/CT is based on interval CT followup [1,2,10,11] instead of actual histology which should be regarded as the gold standard for determining the nature of an adrenal mass, the present study aimed to first evaluate the accuracy of FDG-PET/CT based exclusively on histology and secondly, to identify potential significant factors associated with adrenal metastasis.…”

CT-guided percutaneous core biopsy for assessment of morphologically normal adrenal glands showing high FDG uptake in patients with lung cancer

“…This malignancy rate is comparable to the 72 to 87% malignancy rates reported for hypermetabolic adrenal masses in patients with known malignancy. 3,11,12 Only one procedure failed to demonstrate metastatic spread, which was probably a false negative, although pathological confirmation of lung cancer could not be obtained. Our results agree with those of Villelli et al, who reported that CT-guided core biopsies had 86% sensitivity for malignancy, without on-site evaluation.…”