Tc-99m MIBI uptake in a bronchial carcinoid tumor

A 57-year-old woman had a bronchial carcinoid tumor. Tc-99m MIBI SPECT showed accumulation both on early and delayed images, but there was no activity in the tumor on delayed Tl-201 SPECT. Histopathology and electron microscopy showed carcinoid tumor without oncocytic features. Early uptake and retention of sestamibi in the tumor might be related to the vascularity as well as increased mitochondrial potential.