Figure 1

Macroscopic, microscopic and immunohistochemical features of the acantholytic squamous cell carcinoma of the cecum. (A) Grossly, in the cecoascending region, an ulcero-proliferative, whitish-gray tumor was found. (B) The tumor infiltrated all layers of the bowel wall and spread deeply into the surrounding fatty tissue. (C) Microscopically, the tumor consisted of large, atypical, squamous epithelial cells with abundant keratin formation (H&E, × 100). (D) Large areas of tumor showed prominent acantholythic changes (H&E, × 100). (E) Pseudoglandular formation with detached keratinocytes and inflammatory cells were also detected (H&E, × 100). (F) Tumor cells were large with bright eosinophilic, focally glassy cytoplasm and vesicular nuclei with small to medium sized nucleoli (400×). (G) Immunohistochemically tumor cells were diffusely positive for cytokeratin AE1/AE3 including acantholytic and pseudoglandular area (× 200). (H) Syndecan-1 expression was reduced and confined on small group of detached malignant cell (× 200).