Desmin

When initially identified in 1977, this intermediate filament was given the designation "skeletin". It has a molecular weight of 53 kD. It consists of a headpiece, a tailpiece and an intervening alpha helical midpiece: the latter is highly conserved between species. The three most well-characterised monoclonal antibodies (D33, DER-11 and DEB-5) show no cross-reactivity with other intermediate filaments.

Immunohistochemical expression

Found in smooth, cardiac and striated muscle cells and in lesser amounts in myofibroblasts.  It is more abundant in parenchymal smooth muscle than in vascular smooth muscle.

• rhabdomyoma

• leiomyoma

• rhabdomyosarcoma

• leiomyosarcoma

• desmoid tumour

• myofibroma

• PNETs

• desmoplastic small round cell tumour

• blastemal component of Wilm's tumour¹

• epithelioid sarcoma

• malignant peripheral nerve sheath tumour

• malignant rhabdoid tumour

• sarcomatous malignant mesothlioma

Diagnostic utility

• Identification of smooth muscle and skeletal muscle tumours.

• Differentiation of reactive mesothelial cells (positive) from mesothelioma (negative) and carcinoma (negative) in effusions and histological specimens. For comparison, it is negative in adenocarcinomas².

References

Diagnostic Immunohistochemistry edited by Professor D. J. Dabbs, page 62.

¹Folpe, A. L., Patterson, K., Gown, A. M. Antibodies to desmin identify the blastemal component of nephroblastoma. Mod Pathol 1997;10:895-900.

²Garcia-Prats, M. D., C. Ballestin, et al. (1998). "A comparative evaluation of immunohistochemical markers for the differential diagnosis of malignant pleural tumours." Histopathology 32(5): 462-72.

This page last revised 14.12.2001.

©SMUHT/PW Bishop