The investigation of choice for extra-adrenal pheochromocytoma :
A) MIBG scan
The investigation of choice for extra-adrenal pheochromocytoma is A) MIBG scan.
Pheochromocytomas are tumors that arise from chromaffin cells, which are typically found in the adrenal glands. However, in some cases, pheochromocytomas can occur outside the adrenal glands and are referred to as extra-adrenal or paragangliomas. These tumors can be located in various locations, such as the abdomen, chest, neck, and pelvis.
The most effective imaging modality for localizing and diagnosing pheochromocytomas, including extra-adrenal ones, is the metaiodobenzylguanidine (MIBG) scan. MIBG is a radiopharmaceutical that is taken up by chromaffin cells, making it useful for detecting and localizing pheochromocytomas.
During an MIBG scan, a small amount of radioactive MIBG is injected into the patient’s vein. The MIBG is then taken up by pheochromocytoma cells, and the radioactivity emitted by the tumor can be detected using a gamma camera. This allows for the precise localization of pheochromocytomas, including extra-adrenal ones.
While other imaging modalities such as MRI (B), CT (C), and USG (D) can also provide valuable information in the evaluation of pheochromocytomas, the MIBG scan is considered the investigation of choice for localizing extra-adrenal pheochromocytomas due to its high sensitivity and specificity for detecting these tumors.