The cyst lining shows mainly stratified squamous epithelium. Some cells are ciliated. No adnexal structures are seen. The squamous cells show no nuclear atypia. There are sparse goblet cells. Some of the squamous cells show sebaceous differentiation. A large amount of amorphous granular debris, with cholesterol clefts and multinucleated giant cells is present. There is no glial stroma.
The epithelial cells are CAM5.2, p40, EMA and CEA positive.
S-100, transthyretin and GFAP are negative.
FINAL DIAGNOSIS: neuroenteric cyst.