False Positive Radioiodinated Metaiodobenzylguanidine ((123)I-MIBG) Uptake in Undifferentiated Adrenal Malignant Tumor.
(123)I-Metaiodobenzylguanidine ((123)I-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, (123)I-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 (123)I-MIBG demonstrated by scintigraphy.
Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Hee Soo
HS
Jung
Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Seok Jun
SJ
Moon
Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Yun Mi
YM
Kim
Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Hye Rim
HR
Kang
Department of Nuclear Medicine, Busan Paik Hospital, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Seok Mo
SM
Lee
Department of Pathology, Busan Paik Hospital, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Soo Jin
SJ
Jung
Department of Radiology, Busan Paik Hospital, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Seok Jin
SJ
Choi
Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Tae Kyoon
TK
Kim
Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Min Jeong
MJ
Kwon
Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Jeong Hyun
JH
Park
Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan 614-735, Republic of Korea.
Soon Hee
SH
Lee