Gastrointestinal stromal tumours in patients with neurofibromatosis type 1: A case report and retrospective review of 72 cases

In the present study, the features of gastrointestinal stromal tumours (GIST) in patients with neurofibromatosis type 1 (NF1) are analysed, and the fundamental differences between NF1-associated GIST and the common types of GIST are illustrated. We report a case of NF1-associated GIST, and discuss the clinical and pathological data of 71 reported cases from the PubMed/MEDLINE database over the past two decades. The clinical characteristics, histopathology, biological behaviour, immunohistochemistry, phenotype and gene mutation status of GIST in NF1 are carefully reviewed. A total of 72 cases (35 females and 37 males; median age: 53 years) was included in this study. More than 80 per cent of lesions were located in the small intestine, most of which were multicentric (63.89 per cent), and the median diameter of the tumours was 4cm (range: 0.3-20cm). The positive expression rates for transmembrane type III receptor tyrosine kinase (KIT), CD34, S-100, smooth muscle actin, and desmin were 100 per cent, 94.34 per cent, 37.5 per cent, 35.9 per cent and 7.41 per cent, respectively. There were just six cases found with the KIT gene mutation; no cases were found with mutations in the platelet-derived growth factor receptor- (PDGFRA) gene. Patients with NF1 have a high risk of developing GIST. NF1-associated GIST are significantly different from common GIST in terms of clinical characteristics, histopathology, biological behaviour, immunohistochemistry and the mutation status of the KIT and PDGFRA genes. In addition, in this research, we indicate that different pathogenetic mechanisms are involved in their evolution, and that imatinib has limited effects on GIST in NF1 patients.