PMC3024921_01
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, x 100). (D) Large areas of tumor showed prominent acantholythic changes (H&E, x 100). (E) Pseudoglandular formation with detached keratinocytes and inflammatory cells were also detected (H&E, x 100). (F) Tumor cells were large with bright eosinophilic, focally glassy cytoplasm and vesicular nuclei with small to medium sized nucleoli (400x). (G) Immunohistochemically tumor cells were diffusely positive for cytokeratin AE1/AE3 including acantholytic and pseudoglandular area (x 200). (H) Syndecan-1 expression was reduced and confined on small group of detached malignant cell (x 200).
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F1
Grossly, in the cecoascending region, an ulcero-proliferative, whitish-gray tumor measuring 9 cm in maximum diameter was found (Figure 1A and 1B). Microscopically, the tumor consisted of nests of focally keratinizing, atypical, squamous epithelial cells (Figure 1C). Approximately 70% of the tumor showed acantholytic changes and acantholysis was equally distributed through the entire tumor (Figure 1D). In the lumen-like pseudoglandular spaces, detached keratinocytes and inflammatory cell were detected (Figure 1E). Tumor cells were large with bright eosinophilic, focally glassy cytoplasm and vesicular nuclei with small to medium sized nucleoli (Figure 1F). AE1/AE3 (Figure 1G) and focally positive for epithelial membrane antigen and syndecan 1 (Figure 1H). All other tested antibodies showed negative reaction.
The tumor-cecum mucosa boundary of the acantholytic squamous cell carcinoma of the cecum. (A) The tumor began in the colonic mucosa and was top heavy (H&E, x 40). (B) The tumor-cecum mucosa boundary also indicated primary tumor (H&E, x 200).
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F2
The microscopic features of the tumor-cecum mucosa boundary indicated primary tumor (Figure 2A and 2B) and the diagnosis of acantholytic squamous cell carcinoma of the cecum were suspected.