What type of Doctor or Specialist would handle a pediatric case of Ganlioneuroma Tumors ?

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Male, Age: 12, Indiana

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Pathology and Upper & Lower GI show an erosive lining with ulcerations, and these Tumors diagnosed as Ganglioneuromas which are more uncommonly found in the Spine or the Brain. The fact that they are in his Colon and Digestive Track are extremely rare or so I am told...they have treated the simptoms of ulcerations and the acid promblem, however, no one seems to know what to due for a more permanent cure. The Tumors that have been biopsied are benign, however, it is my understanding that they secret something that causes his immune system to attack or go into overdrive which creates a host of other simptoms. Simply put my son has recurring and cronic pain that takes any assemblance of a normal life away from him....the specialist we are seeing, a GI Dr, A Neurologist and an Allergist seem stumped and where to go next, I am not happy with just treating the symptoms as they occur....I want a diagnoses and prognoses and if these Tumors are causing all the pain who or what Doctor removes them ?