Leiomyosarcoma

Histopathology

Leiomyosarcoma show fascicles of spindle cells with eosinophilic delicately fibrillary cytoplasm, hyperchromatic blunt-ended (cigar-shaped) nuclei and paranuclear vacuoles. There may be myxoid areas or metaplastic bone formation.

Variants:

Pleomorphic leiomyosarcoma

Immunohistochemistry

desmin	50-100%	relatively specific
SMA	90%	less specific
HHF35	positive	not specific
Pancytokeratin	38/1001
Cytokeratin 1	0/101
Cytokeratin 5/6	1/121
Cytokeratin 7	0/121
Cytokeratin 8 / 18	14/401
Cytokeratin 13	0/191
Cytokeratin 14	1/121
Cytokeratin 19	1/191
Cytokeratin 20	0/121
S-100	occasional
Leu-7	occasional
b-catenin	occasional
myelin basic protein	occasional

Further information is available on these tumours at specific sites:

Differential diagnosis: see the immunohistochemistry of the differential diagnosis of spindle cell stromal tumours.

References

1Chu, P. G. and L. M. Weiss (2002). "Keratin expression in human tissues and neoplasms." Histopathology 40(5): 403-39. (Summary data from multiple papers)

This page last revised 4.1.2004.