Inflammatory myxohyaline tumor with massive emperipolesis

We report on a 36-year-old man with a recurrent mass on the thenar side of the right hand. Against the background of dense inflammation, inflammatory malignant fibrous histiocytoma was first diagnosed, but typical morphologic features in the recurrent tumor led to a correction of the diagnosis--inflammatory myxohyaline tumor. Massive emperipolesis of the neoplastic cells, forming the so-called "cell microabscesses", dominated the histologic picture in both primary and recurrent lesions. Awareness of this unique feature helps in differentiating this entity from both benign inflammatory processes and clearly malignant tumors.