Background: Primary subcutaneous leiomyosarcoma is a rare neoplasm composed of plump, elongated spindle cells arranged in interweaving fascicles.
Objective: Differential diagnosis might be facilitated by the use of immunohistochemistry.
Methods: A case of subcutaneous leiomyosarcoma was investigated histologically on paraffin-embedded tissue and immunohistochemistry was performed following standard procedures.
Results: The case reported exhibited light microscopic features and an immunophenotype characteristic of leiomyosarcoma. However, the intermediate filament desmin could only be found on a small number of tumor cells.
Conclusion: Expression of these markers might vary considerably and immunoperoxidase stainings need to be carefully evaluated. Utilization of several antibodies directed against different desmin epitopes might be advantageous.