Gallium and thallium scintigraphy in pediatric peripheral primitive neuroectodermal tumor (Askin tumor) of the chest wall.

A 3.5-yr-old child presented with a large thoracic mass which showed avid accumulation of 67Ga and 201Tl was studied. Histology showed a peripheral neuroectodermal tumor of the chest wall typical of the malignancy described as the Askin tumor. The 201Tl studies were a more accurate method of following tumor response to therapy than 67Ga scintigraphy.