Squires MH, et al. - In this cohort study involving 71 individuals, researchers compared quantified intraoperative parathyroid autofluorescence imaging results for patients with multiple endocrine neoplasia type 1 (MEN1)-associated vs those with non-MEN1 sporadic primary hyperparathyroidism. According to findings, nonparathyroid fibroadipose tissue in MEN1 patients displayed higher background autofluorescence, resulting in high false-positive rates (5 of 6 patients [83%]) vs only 3 of 65 (5%) false-positive autofluorescence nonparathyroid specimens in patients without MEN1. In patients with primary hyperparathyroidism, intraoperative detection of parathyroid glands using their autofluorescence by real-time near-infrared imaging tends to be useful. In this initial cohort of patients with MEN1, reduced parathyroid autofluorescence and increased background autofluorescence of nonparathyroid tissue can be linked to high rates of false-negative and false-positive fluorescence, potentially restricting the utility of this adjunct in this particular subset of patients.