A Rare Association Between Gastrointestinal Stromal Tumor and Neurofibromatosis Type 1: A Case Report.

The association between gastrointestinal stromal tumor (GIST) and neurofibromatosis type 1 (NF1) has been documented in medical literature but remains rare. We report a 53-year-old male patient who was investigated extensively for months for lower gastrointestinal tract (GIT) bleeding that remained obscure despite upper and lower endoscopies as well as a barium follow-through. His past medical history is significant for NF1 with numerous cutaneous neurofibromas as well as café au lait spots and bilateral functional pheochromocytoma status post-bilateral adrenalectomy. However, the progression of his bleeding as well as iron deficiency anemia prompted more aggressive investigations. These have revealed a small bowel mass that proved to be GIST on histological and immunohistochemical staining examination. This case helps remind clinicians of the important association between NF1 and GIST, and the clinical pearl that most GISTs in NF1 are located in the small intestine and may not be apparent on endoscopy with barium follow-through and require push enteroscopy to allow for better localization.