Gastrointestinal Autonomic Nerve Tumor (GANT)
Definition
- Gastrointestinal stromal tumor (GIST) with ultrastructural features of neural differentiation
Alternate/Historical Names
- Plexosarcoma
Diagnostic Criteria
- GANT is currently considered to fall within the spectrum of GIST
- They may simply be diagnosed as GIST
- See GIST for detailed criteria, grading, differential diagnoses and bibliography
- Light microscopic features are identical to GIST
- May be spindled or epithelioid
- Ultrastructural study have claimed to show features of neural differentiation
- Complex long thin interdigitating cell processes
- Processes joined by rudimentary cell junctions
- Neurosecretory granules
- Synapse-like structures
- Immunohistochemical features are essentially the same as GIST
- Some reports have described chromogranin and synaptophysin staining
- No such staining was identified in a more recent study (Lee 2001)
- Neuron specific enolase is positive but is not considered a specific marker
- 100% CD117 positive, 58% CD34 positive
- S100 variably reported, mean 39%
- Genetic study has revealed mutations in KIT gene
- Clinical behavior is same as GIST
- We do not make this diagnosis
- Reference
- Lee JR, Joshi V, Griffin JW Jr, Lasota J, Miettinen M. Gastrointestinal autonomic nerve tumor: immunohistochemical and molecular identity with gastrointestinal stromal tumor. Am J Surg Pathol. 2001 Aug;25(8):979-87
Teri A Longacre MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting :December 5, 2009
