RESUMO
OBJECTIVE: Laminin-5 γ2 chain (LNγ2) plays an important role in cancer differentiation and migration. Using a novel immunohistochemical mapping technique to investigate whole mucosal strips of total laryngopharyngectomy specimens using iodine, H-E, and LNγ2 stainings, we investigated the locoregional behavior of hypopharyngeal cancer. METHODS: Surgical specimens from two patients with pyriform sinus cancer were investigated. Three percent iodine was applied to the tumor-bearing laryngopharynx during surgery and photographed. Stainabilities of H-E and LNγ2 on pathologic sections from all mucosal strips were scored and coordinated with the laryngopharyngeal photograph to illustrate the immunohistochemical map. RESULTS: In both patients, the main tumor of invasive squamous cell carcinoma was circumferentially surrounded by a superficial lesion characterized by high grade intraepithelial neoplasia that remained unstained by iodine. On LNγ2 immunohistochemical mapping, the main tumor was demonstrated by Score 2 staining and the superficial lesion by a stronger Score 3 staining. CONCLUSIONS: The finding of neoplastic cells at the periphery demonstrating a higher potential than the cancer cells at the tumor center is suggestive of impending progression from neoplasia to carcinoma. The current preliminary report suggested morphological evidence of intraepithelial infiltration and lateral invasion in hypopharyngeal cancer.