Unusual Causes of I-131 Metaiodobenzylguanidine Uptake in Non-neural Crest Tissue

False-positive radio-iodinated metaiodobenzylguanidine (123I-MIBG) accumulation in a mast cell-infiltrated infantile haemangioma

“…The high specificity of 123 I-MIBG accumulation is useful for the classification of tumours, such as pheochromocytomas, neuroblastomas or carcinoids, in the area of the I-MIBG uptake have been described, including haemangiomas [6,7].…”

“…This specific uptake and storage mechanism provides the basis for the imaging of neuroendocrine tumours such as pheochromocytomas and neuroblastomas. Nevertheless, cases of false-positive 123 I-MIBG scintigraphy with accumulation in non-chromaffin tumours such as angiomyolipoma [3], adrenocortical carcinoma [4], adrenocortical adenoma [5], juvenile capillary angioma [6] or cavernous haemangioma [7] have been described. Here, we present another case of a falsepositive 123 I-MIBG scan of a tumour within the adrenal gland area and discuss the possible mechanism.…”

False positive MIBG scan due to accessory spleen

“…MIBG has an extremely high speci®city in detecting neuroendocrine tumors. However, non-chromaf®n masses may rarely show MIBG uptake: infantile myo®bromatosis [4,5], pancreaticoblastoma [4], adenomatous polyp of the colon [3], atrophic kidney [6], cavernous hemangiomas [6,7], schwannoma, adrenal adenoma, and adrenal metastasis of choriocarcinoma [8] have been described. The mechanism causing these false positive results has not been entirely understood so far.…”

123I-Methyljodbenzylguanidin- (MIBG-) Szintigraphie

“…paradoxer Nuklidspeicherung, die sich klinisch und biochemisch unter dem Bild eines Phäochromozytoms präsentieren und operiert werden, eine Seltenheit. Das Phänomen der paradoxen Nuklidspeicherung wurde bislang bei 5 weiteren (jeweils nichtonkozytären) NNR-Karzinomen [1,7,13,16] und bei 5, teilweise MEN-2-assoziierten NNR-Adenomen [6,11,12,21,22] beschrieben.…”