Neurofibromatosis type 1 associated gastrointestinal stromal tumors

Objective:To investigate the pathologic feature,immunophenotype and particularity of neurofibromatosis type 1 (NF1) accompanied with multiple gastrointestinal stromal of tumors (GIST).Methods:The clinical manifestation,histopathology and immunophenotype of the case of NF1 accompanied with GIST were analysed,and reviewed of the literatwre was reviwed.Results:The patient was a 46-year-old woman with a history of cutaneous nodules for 28 years,did not take any treatment.When she pregnanted after marriage,the cutaneous nodules number increased,and involving the face,trunk and limbs for over the entire skin surface.Recently,paroxysmal pain in the lower abdomen was appeared.The ultrasound revealed substantial masses in the abdomen.The subserosal nodules in the jejunum and the ileum were found at surgery,about a dozen more.The partial jejunum and the subserosal nodules (2 tumors) were resected.At the time of the procedure,one of the cutaneous lesions was also sampled.Tumor cells of the jejunum and ileum were rich in spindle-shaped or oval,small nucleoli,mitotic figures to be seen.Immunophenotype:(1) tumors located in the jejunum and ileum were positive for vimentin (3+),CD117 (2+),CD34 (2+),MSA (1+),negative for S-100 protein,low expression of Ki-67; (2) skin nodule on the left forearm:S-100 protein (3+),CD117 (-),CD34 (-),MSA (-).No chemoradiation therapy after resection,at the 7th month,the patient was in good condition.Conclusions:NF1 associated GIST typically involves the small intestine and may be multifocal.The tumors are spindle cell in type with cellularity,low mitotic activity and low-grade.