Immunohistochemistry in the differential diagnosis of tumours of possible myogenic origin.

A series of 34 cases of soft tissue tumours of possible muscle origin was studied immunohistochemically using different antibodies. Tissue specimens and/or aspirates from fine needle aspiration biopsy (FNAB) were examined. The results indicate that immunohistochemistry is a valuable tool in differential diagnosis of soft tissue tumours, improving diagnostic accuracy in 83.5% of the examined cases. Desmin expression confirmed muscle differentiation of tumours in 47.6% of diagnostically difficult cases. The application of immunohistochemistry may be especially helpful in rendering the diagnosis of tumour type more precise when a needle aspirate is the only available diagnostic material.