In our first case (patient 1), the tumor, a typical carcinoid (well-differentiated neuroendocrine carcinoma), was not localized with CT and an octreotide scan result was negative. However, the tumor did show up as a focal “hot spot” on subsequent PET scanning (Fig 1
). A gated MRI of the hot spot gave further, accurate localization. PET scanning therefore localized the tumor when other modalities had failed. In the second case (patient 2), an atypical carcinoid (moderately differentiated neuroendocrine tumor), the tumor was localized with a CT scan of the chest but subsequent PET scan revealed an unsuspected metastasis in the lumbar spine (Fig 2
). The lumbar metastasis required orthopedic fixation before the surgery to remove the mediastinal tumor. Octreotide scanning was not performed in patient 2, but MIBG scanning revealed the same distribution of metastases as the PET scan, and the patient received radioactive (I131) MIBG treatment.