Multiple small intestinal stromal tumours in a patient with previously unrecognised neurofibromatosis type 1: Immunohistochemical and ultrastructuralevaluation

Neurofibromatosis type 1 could be associated with multiple gastrointestinal stromal tumours, although their presence is not considered among the major diagnostic criteria. We present here a case of a 50-year-old female compla ining of abdominal pain, with about 100 small intestinal stromal tumours. T his finding prompted us to suspect a neurofibromatosis which was clinically confirmed afterwards. Light microscopy examination revealed a low-grade st romal tumour with skeinoid fibres. Mixed neural-interstitial cells of Cajal origin or, alternatively, neural differentiation of interstitial cells of Cajal are discussed on the basis of immunophenotype (CD 117 +, CD34 +) and ultrastructure. A 2-year follow-up did not indicate an aggressive course in the case of this neoplasm.