Immunohistochemical analysis and biological behaviour of gastric glomus tumours: a case report and review of the literature.

Gastric glomus tumours are rare and clinically recognized as benign. Nevertheless, some show biological behaviour similar to that of malignant lesions. During the last 40 years, we have encountered only one gastric glomus tumour. Analysis of frozen sections of this tumour suggested a mesenchymal tumour with malignant potential. Three mitoses per 50 high-power fields, with no cytological abnormalities, were observed. Tumour cells were positive for α-smooth muscle actin, vimentin and actin but negative for CD117, S-100 protein, creatine kinase, desmin, CD68, collagen type IV, CD34 and p53. The post-operative period was uneventful. During 37 months' follow-up, no recurrence or metastasis was detected and a benign course was considered likely. Literature on the immunohistochemistry and biological behaviour of gastric glomus tumours was also reviewed. Immunohistochemical studies are helpful in the differential diagnosis of gastric glomus tumours: although most are benign, malignancy cannot be excluded. Thus, long-term follow-up of the patient is necessary.