123I-Metaiodobenzylguanidine (123I-MIBG) scintigraphy is a widely used functional imaging tool with a high degree of sensitivity and specificity in diagnosis of pheochromocytoma.
However, rare cases of false positive reactions have been reported. A 67-year-old male patient was admitted with epigastric pain. Abdominal computed tomography (CT) revealed a heterogeneous left adrenal mass 6 cm in diameter; following hormone testing, 123I-MIBG scintigraphy was performed to determine the presence of pheochromocytoma, which confirmed eccentric uptake by a large left adrenal gland mass. Chest CT and PET-CT confirmed metastatic lymphadenopathy; therefore, endobronchial ultrasound transbronchial needle aspiration was performed. Metastatic carcinoma of unknown origin was suspected from a lymph node biopsy, and surgical resection was performed for definitive diagnosis and correction of excess hormonal secretion. A final diagnosis of undifferentiated adrenal malignant tumor was rendered, instead of histologically malignant pheochromocytoma, despite the uptake of 123I-MIBG demonstrated by scintigraphy.
Written by:
Jung HS, Moon SJ, Kim YM, Kang HR, Lee SM, Jung SJ, Choi SJ, Kim TK, Kwon MJ, Park JH, Lee SH. Are you the author?
Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea; Department of Nuclear Medicine, Busan Paik Hospital, College of Medicine, Inje University, Busan 614-735, Republic of Korea; Department of Pathology, Busan Paik Hospital, College of Medicine, Inje University, Busan 614-735, Republic of Korea; Department of Radiology, Busan Paik Hospital, College of Medicine, Inje University, Busan 614-735, Republic of Korea; Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Reference: Case Rep Oncol Med. 2015;2015:164280.
doi: 10.1155/2015/164280
PubMed Abstract
PMID: 25918656