Granular cell tumor of the stomach

Granular cell tumors are peripheral neuroectodermal tumors. Within the gastrointestinal tract, they have to be differentiated from gastrointestinal stromal tumors (GIST). We present the case of a 61-year-old patient who was diagnosed with a granular cell tumor of the stomach. The tumor cells showed transmural infiltration form the mucosa into the adipose tissue of the lesser curvature. The tumor cells were diffusely positive for S100-protein and negative for KIT, CD34 und SMA. The MIB1-proliferation index was below 2%. Granular cell tumors rarely occur within the gastrointestinal tract. Oesophagus and colon are most commonly affected. Diagnostic criteria and differential diagnosis of this peculiar lesion are thoroughly discussed.