Teaching Case

The patient referred to one year with bloating and mild epigastric pain.

The patient referred a one year bloating and epigastric pain. For this reason he underwent some medical examinations. He made a gastric endoscopy which documented three polypoid neoformations to subcardial region, antrum and juxta-pyloric region. He underwent biopsy of the antrum lesion, which demonstrated a gastrointestinal stromal tumour. After two months he underwent CT for staging, which showed two masses. The bigger was localized on the lesser curve of the stomach (Fig 1,2); it was 34x37x46 mm in size and had a heterogeneous contrast-enhancement during both the arterial and the venous phase. The other one was in the juxta-pyloric region (Fig 3-5); it was 42x43x47 mm in size. Both have a great transmural extension. There were no metastases.

Gastrointestinal stromal tumours (GISTs) are rare, but are the most common nonepithelial tumours of the GI tract. They arise from a precursor of the interstitial cells of Cajal anywhere along the gastrointestinal tract, but they are most common in the stomach (70%) and small bowel wall (20%), within the muscularis propria. GISTs are usually solitary tumours which occur in middle-aged to older individuals.
The clinical manifestations depend on the localization and size of tumour, but often they are nonspecific, e.g. abdominal pain, early satiety, bloating, nausea and vomiting; large GISTs can cause weight loss, gastrointestinal bleeding because of the involvement the mucosa or a palpable mass; bowel obstruction and ascites are rare. For this reason diagnosis is often late and sometimes GISTs are incidentally discovered during radiologic evaluation or surgical procedure performed for other reasons.
Diagnosis is made histological; CD-34 and CD-117 positivity is required. CT is used for staging. In CT they appear as single or multiple large, exophytic, hypervascular masses. Sometimes small tumours are polypoid endoluminal neoformations. Large masses are often heterogeneous because of haemorrhage, necrosis and cystic degeneration, particularly in the late stage of the disease.
Because of frequent late diagnosis, half of the patients have metastases, commonly in the liver and the peritoneum. Lymph nodes involvement is not frequent.
GISTs have to be differentiated from other GI cancers: lipomas, fibromas, leiomyomas, adenocarcinomas, lymphomas, carcinoids, leiomyosarcoma and metastases.
Localised GISTs are treated by means of surgical resection, while advanced GIST can be treated with tyrosine kinase receptor blockers. Prognosis is better for patients with an early diagnosis.