Auerbach's myenteric plexus. A possible site of origin for gastrointestinal stromal tumors in von Recklinghausen's neurofibromatosis.

We present a case of multiple benign spindle cell tumors of the jejunum in a patient with von Recklinghausen's neurofibromatosis and describe the light-microscopic, immunohistochemical, and ultrastructural features of these lesions. Two small spindle cell nodules were located in the region of Auerbach's myenteric plexus and a third larger tumor produced a subserosal mass. The immunohistochemical profile of these tumors revealed that they were actin and S100-protein negative but positive for neuron-specific enolase. At the ultrastructural level, the tumors recapitulated features of Auerbach's plexus. These lesions are similar to previously described gastrointestinal autonomic nerve tumors, and we propose that this may be the site of origin of enteric stromal tumors in von Recklinghausen's neurofibromatosis.