Methods: Two ASCs and 1 ASC went through microscopic examination and a panel of immunohistochemical stain including; cytokeratin-pan, high-molecular-weight cytokeratin (HMWCK), cytokeratin7 (CK7) and carcinoembryonic antigen (CEA).
Results: Both ASC and ASCC seemed to originate from the surface epithelium and exhibited tubular structures in the tumor nests. In microscopic examination, the tubular structures of ASCs were lined by cuboidal, basaloid, or small round cells which are suggested to be reminiscent of the glandular differentiation of adenocarcinoma. In contrast, the gland-like structures of ASCC seemed to be formed by acantholysis and not surrounded by true ductal lining epithelium. On immunohistochemical studies, the glandular component of ASC showed positivity to CK7, CEA and HMWCK, while the pseudoglandular structures of ASCC exhibited focal positivity to HMWCK but negativity to CK7.
Conclusion: The differences in histological features of ASC and ASCC and immunohistochemical reactivity to CK7 and HMWCK lead towards differentiating ASC and ASCC.