Caldesmon by IHC-12376 - Technical only, 12379 - Technical & interpretation

Test info

Caldesmon by IHC
12376 - Technical only, 12379 - Technical & interpretation
  • All IHC stains will include a positive control tissue
  • The primary use for this antibody is in identifying cells and tumors of smooth muscle origin
  • Caldesmon will react with leiomyomas and leiomyosarcomas
  • This antibody has not been found to significantly react with tumors of skeletal muscle or myofibroblastic origin (less than 1% of cells in MFH tumors have shown some staining)
  • This marker will also react with glomus tumors
  • Caldesmon will react with benign myoepithelial cells, however neoplastic myoepithelial tumors and mixed tumors of salivary gland and skin show no reactivity
  • This antibody has also been used to identify the myoepithelial layer surrounding benign breast proliferations (can be used as an adjunct to SMMS)



Submit a formalin-fixed, paraffin embedded tissue block


Formalin-fixed, paraffin embedded (FFPE) tissue block


FFPE tissue section mounted on a charged, unstained slide


Ambient (preferred)

  • Unlabeled/mislabeled block
  • Insufficient tissue
  • Slides broken beyond repair


AHL - Immunohistochemistry
Mo - Fr
1 - 2 days

Immunohistochemical staining and microscopic examination

Clinical and Interpretive info


If requested, an interpretive report will be provided



  • Caldesmon is a protein which is reported to be specific for smooth muscle cells
  • The h-isoform (this antibody) identifies only vascular and visceral smooth muscle cells; the l-isoform (which our antibody does not recognize) is found in many other kinds of cells
  • It combines with calmodulin, tropomyosin, and actin and is thought to regulate cellular contraction
  • Caldesmon has not been identified in skeletal muscle

Staining pattern

  • Cytoplasmic based activity


  1. Ceballos KM et al. Is anti-h-caldesmon useful for distinguishing smooth muscle and myofibroblastic tumors? An immunohistochemical study. Am J Clin Pathol, 2000,; 114:746-753.
  2. Watanabe K et al: H-caldesmon in leiomyosarcoma and tumors with smooth muscle cell-like differentiation: its specific expression in the smooth muscle cell tumor. Hum Pathol, 1999,; 30:4; 392-396.
  3. Wang NP et al: Antibodies to novel myoepithelium associated proteins distinguish benign lesions and carcinoma in situ from invasive carcinoma of the breast. Appl Immunohistochemistry 1997; 5(3) 141-151.


88342 - 1st stain
88341 - each additional stain