All IHC stains will include a positive control tissue

• DOG1 has a reported sensitivity of 94% to 100% in gastrointestinal stromal tumors (GIST)
• DOG1 is more sensitive than CKIT (CD117) in detecting GIST tumors of gastric origin, tumors with epithelioid morphology, and tumors harboring PDGFRA mutations
• Thus, DOG1 staining may be a useful adjunct to confirm an epithelioid or gastric GIST and discriminate from leiomyosarcomas (which can be CKIT positive)
  Note: approximately 1-2% of GISTS of the GI tract will be negative for both DOG1 and CKIT

Submit a formalin-fixed, paraffin-embedded tissue

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

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• Calcium-regulated chloride channel protein

Staining pattern

• Membranous and cytoplasmic staining

Expected normal staining:

• DOG1 is positive in the following normal tissues: Cajal cells of the gastrointestinal tract, luminal surface of the gastric mucosa, salivary gland, pancreatic acini, intrahepatic bile ducts, gallbladder, bladder, breast and prostate myoepithelial/basal cells
• DOG1 positivity has been described in rare cases of leiomyosarcoma, peritoneal leiomyomatosis, synovial sarcoma, and desmoplastic melanoma
• DOG1 positivity has also been described in the following carcinomas/epithelial neoplasms: hepatocellular carcinoma, basal cell adenoma, adenoid cystic carcinoma, lung adenocarcinoma, and GI tract carcinomas.
• DOG1 positivity has been described in dendritic-shaped Cajal cells which can colonized intramural GI leiomyomas

References

1. Espinosa et al. A Novel monoclonal antibody against DOG1 is a sensitivity and specific marker for gastrointestinal stromal tumors; Am J Surg Pathol 2008;32(2):210-218.
2. Miettinen et al. DOG1 antibody in the differential diagnosis of gastrointestinal stromal tumors. Am J Surg Pathol 2009;33(9):1401-1407.
3. Hwang et al. DOG1 antibody is highly sensitive and specific marker for gastrointestinal stromal tumors in cytology cell blocks. Am J Clin Pathol 2011;135:448-453.
4. Lopes et al. DOG1 for the diagnosis of gastrointestinal stromal tumor (GIST): Comparison between 2 different antibodies. Appl Immunohistochem Mol Morphol 2010;18(4):333-337.