Immunohistochemical panel for distinguishing esophageal adenocarcinoma from squamous cell carcinoma: a combination of p63, cytokeratin 5/6, MUC5AC, and anterior gradient homolog 2 allows optimal subtyping
Human Pathology, 07/06/2012
DiMaio MA et al. – Overall, the dual expression of both p63 and cytokeratin 5/6 was 99% specific and 98% sensitive for squamous cell carcinoma. In addition, anterior gradient homolog 2 and MUC5AC are useful positive markers of adenocarcinoma in the setting of absent or diminished p63 and cytokeratin 5/6 staining.
Methods- We analyzed commonly used immunohistochemical markers (p63, cytokeratin 5/6, cytokeratin 7, CDX2, MUC2, and MUC5AC) and 2 new markers, anterior gradient homolog 2 and SOX2, in esophageal carcinomas to establish the best panel to distinguish these tumors.
- Tissue microarrays with 69 esophageal adenocarcinomas and 41 whole sections of esophageal squamous cell carcinomas were stained for these markers and semiquantitatively scored.
- Sensitivities and specificities were calculated for individual markers and select combinations using the morphological diagnosis as a gold standard.
- All squamous cell carcinomas expressed p63 with 38 of 41 demonstrating reactivity in more than 75% of tumor cells.
- Cytokeratin 5/6 expression was seen in 40 of 41 squamous cell carcinomas with 39 of 41 demonstrating reactivity in more than 75% of tumor cells.
- SOX2 expression was present in 35 of 41 of squamous cell carcinomas but also in 24 of 69 of adenocarcinomas, frequently demonstrating extensive reactivity in adenocarcinomas.
- Anterior gradient homolog 2 was highly sensitive for adenocarcinoma and present in 68 of 69 of cases, but anterior gradient homolog 2 reactivity was also identified in 15 of 41 of squamous cell carcinomas, typically demonstrating focal reactivity in squamous cell carcinoma.
- MUC5AC expression was seen almost exclusively in adenocarcinomas with only a single squamous cell carcinoma demonstrating focal MUC5AC staining.
