Mesenchymal neoplasms are often accompanied by a sparse lymphocytic infiltrate. Some tumors, however, are characterized by the presence of specific types of inflammatory cells including lymphocytes, plasma cells, histiocytes, eosinophils, neutrophils, and mast cells. The presence of a type or combinations of inflammatory cells may be a diagnostic clue or may obscure the neoplastic process. It is prudent to use these in combination with other clues to develop a differential diagnosis. We provide a brief review of soft tissue neoplasms in which inflammatory cells are of diagnostic significance.