eComment. gastrointestinal stromal tumours.

We would like to comment on the case report by Kim and colleagues concerning the surgical treatment of a gastrointestinal stromal tumour in the posterior mediastinum [1]. Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract (5000 new cases per year in the United States) [2]. They can be found in patients with a median age of 60 y, with frequent occurrence (70%) in the muscular wall of the stomach, followed by small bowel (10-20%), oesophagus, omentum, mesentery and retroperitoneum [2,3]. GISTs can range from small benign tumours to sarcomas at all sites of occurrence. Tumours that have metastasized at presentation have a very poor prognosis. The 5-year survival in patients with malignant GISTs is less than 40% [2]. There are three key prognostic factors: mitotic rate, tumour size, and site. Tumours that are small (=2 cm) and show mitotic activity not exceeding 5 mitoses per 50 high-power fields, have an excellent prognosis. This prognosis probably is independent of site, although this has not been shown specifically for all sites. In the stomach, most epithelioid GISTs are benign. However, we have to bear in mind that a small proportion of tumours apparently lacking mitotic activity do metastasize [2,3]. GISTs in association with paragangliomas and pulmonary chondromas constitute the Carney triad. In fact, the ‘Carney triad’ is a multiple neoplasia syndrome affecting mostly females. This syndrome - or Carney complex - predisposes to a variety of tumours including adrenocortical adenomas (unilateral or bilateral) that are usually non-functioning [2,4]. Carney and Stratakis, in 2002, distinguished the inherited GISTs with paraganglioma syndrome from the Carney triad as an autosomal dominant condition in adult patients. This condition has been called Carney-Stratakis syndrome [5]. These two syndromes, even though quite rare, have entered the realm of multiple endocrine neoplasias in the last years. Carney-Stratakis syndrome is probably more frequent and may be prevalent amongst patients with GISTs that are negative for KIT/PDGFRA mutations [2]. A high index of suspicion is required by surgeons who are dealing with patients with isolated or sporadic GISTs or paragangliomas. They have to be aware of the Carney and Carney-Stratakis syndromes. A multidisciplinary diagnostic approach regarding the medical and family history of the patients is of paramount importance (especially in the younger patient with KIT or PDFGRA mutation-negative GISTs) [2]. Conflict of Interest: None declared