Primary gastric inflammatory myofibroblastic tumor:a clinicopathologic study / 临床与实验病理学杂志

ABSTRACT

Purpose To investigate the clinicopathologic features, diagnosis and differential diagnosis of primary gastric inflammatory myofibroblastic tumor ( IMT) . Methods Four cases of gastric IMTs were studied by clinicopathologic analysis, immunohistochemistry and in situ hybridization, and the related literature was reviewed. Results In four cases there are two males and two females, age range from 21 to 51 years old, and tumor size ranged from 1. 5 to 6. 5 cm in the greatest dimension. Histologically, these tumors were composed of varied spindle cells and chronic inflammatory cells, in a myxoid or hyalinized stroma. Occasionally, there were calcifica-tion and ossification areas. Most of the spindle cells had bland appearance and a minority of the tumor cells showed mild atypia. One to two mitotic figures were recognized in 10 high power fields ( HPFs) in 1 to 2 patients. Smooth muscle actin staining was observed in all tumors and ALK staining observed in two tumors. One tumor focally expressed CD34. S-100, desmin, CD68, CD117 and DOG1 was negative in all IMTs. The patients were followed up from 24 to 66 months, and none of them had tumor relapsed or metastasis. Conclu-sions Primary gastric IMTs have an intermediate behavior, and a few cases have malignant potential. It should be distinguished from other spindle cell lesions similar to IMT.