Endocrine Abstracts

Neuroblastoma is a tumor that originates from immature nerve cells. It is the most common extracranial solid tumor in children, but is extremely rare in adults.

Aim: The role of MIBG scintigraphy in diagnosis and follow-up of patient with neuroblastoma.

Case report: A 55-year-old woman underwent for regular abdomen ultrasound examination. Sonography revealed inhomogeneous, predominantly isoehogenic tumor mass above the upper lobe of the right kidney, measuring 34×45×42 mm. She has been without simptoms. MSCT of abdomen revealed tumor mass in the right adrenal gland that measured 35×45×44 mm. The cathecholamine levels were normal. Laparoscopic right adrenalectomy was done. Pathohistological diagnosis was neuroblastoma. Immunohistochemical profile showed positive chromogranin A, neuron-specific enolase, synaptophysin. Proliferative activity (Ki-67) was 25%. After post-operative recovery scintigraphy with I-131-MIBG and FDG-PET for staging performed and it was negative. MR of abdomen was performed four months and ten months after operation and was negative. Because of neuron-specific enolase elevation, whole body MIBG scintigraphy with SPECT/CT was done. Thyroid blocade with Na-perchlorate had been srarted 30 min before injection of I-131-MIBG and continued during next five days. I-131-MIBG was intravenously applyed in dose of 37 MBq (1 mCi).

Results: Whole body planar scintigrams were performed 24 and 48 hours postinjection and showed intensive focal radiotracer accumulation in the right hemiabdomen. SPECT/CT confirmed accumulation of I-131-MIBG probably in lymph node in the right hemiabdomen, in front of the right crus of diaphragm, at the level of the upper mesenteric artery. The patient underwent extirpation of tumor mass and pathohistology confirmed metastatic neuroblastoma in lymp node.

Conclusion: MIBG scintigraphy with SPECT/CT is very important modality in diagnosis, staging and follow-up of patients with neuroblastoma because it is relatively simple method, with high sensitivity and specificity.