Extraosseous localization of 99mTc-MDP in ganglioneuroblastoma.

A 2 1/2-year-old boy with a posterior mediastinal ganglioneuroblastoma was evaluated by bone scintigraphy using 99mTc-DMP and showed a marked increased uptake in the tumor mass. Although a routine chest X-ray and body CT scan failed to demonstrate calcification, X-ray examination of the removed tumor specimen revealed small scattered calcification. The proposed mechanisms of the radiopharmaceutical localization in benign and malignant tumors other than calcification/mineralization are discussed. Regardless of the mechanism, localization of a bone scanning agent in a tumor provides a rapid, simple, and noninvasive means of demonstrating tumor size, configuration, and the relation of the surrounding structures to the tumor.