An immunohistochemical examination of basaloid squamous cell carcinoma of the esophagus: report of a case

Liver metastatic basaloid squamous cell carcinoma with negative expression of pancytokeratin: a case report and literature review

Background

Basaloid squamous cell carcinoma (BSCC) is a rare subtype of squamous cell carcinoma with a high rate of distant metastasis. BSCC occurs most commonly in the esophagus, lungs, and head and neck. However, BSCC occurring in an atypical site without a known primary tumor and/or with the presence of atypical immunohistochemical features can result in delayed diagnosis or misdiagnosis.

Case presentation

Here, we report a case of a 67-year-old man with liver metastatic BSCC with negative pancytokeratin (AE1/AE3) expression. He presented with a chief complaint of epigastric discomfort. Imaging examination revealed a subcapsular mass in the right anterior lobe of the liver. Then, the patient underwent an irregular right hepatectomy. Grossly, the mass was gray, with a size of 7 × 7 × 4 cm. Microscopically, the mass comprised epithelioid tumor cells with both solid and pseudoadenoid structures, accompanied by necrosis. Immunohistochemical staining showed that the tumor cells were negative for AE1/AE3, CK18, CK7, CK19, Hepatocyte Paraffin-1, Glypican-3, Arginase-1, CD56, Chromogranin A, Synaptophysin, Vimentin, and Carcinoembryonic antigen. The Ki-67 index was 80%.The mass was diagnosed as a malignant tumor but could not be classified further. One month after surgery, the patient’s reexamination revealed esophageal tumor, and biopsy revealed BSCC. The slides of the liver tumor were reviewed, and the morphology was similar to that of the esophageal tumor. Moreover, supplementary immunohistochemical staining of liver tumor indicated p63 and p40 were strongly positive, that confirmed the liver tumor was metastatic BSCC. Previous studies have reported that 3.7% of esophageal BSCCs did not express AE1/AE3.

Conclusion

When a malignant tumor comprises epithelioid cells with solid and/or pseudoadenoid structures, but not adenocarcinoma or neuroendocrine carcinoma, even if the tumor cells are negative or weakly positive for AE1/AE3, we should consider BSCC. For a definite diagnosis, immunohistochemical staining for squamous cell carcinoma markers, including p63 and p40, and examination of common primary sites of BSCC should be performed.

A novel gene expression scoring system for accurate diagnosis of basaloid squamous cell carcinoma of the esophagus

Basaloid squamous cell carcinoma of the esophagus (BSCE) is a rare variant of squamous cell carcinoma that is difficult to distinguish from other carcinomas by preoperative endoscopic biopsy because of its histological varieties. Accurate diagnosis is essential for adequate treatment, and the methods proposed so far (e.g., immunohistochemical staining) have limitations. In this study, we tried to identify the characteristic bundles of gene expression in BSCE using comprehensive gene expression analysis (CGEA). Subsequently, we constructed a gene expression scoring system for the proper diagnosis of BSCE. Fifty-seven surgical specimens, including seven BSCEs, obtained from 30 patients who underwent esophagectomy were used for constructing the scoring system. Three hundred and twelve biopsy specimens, including eight BSCEs, obtained from 80 patients and 20 commercially available formalin-fixed paraffin-embedded (FFPE) specimens diagnosed as esophageal cancer, including 13 BSCEs, were used for validation. After our original mathematical extraction algorithm, 75 genes were extracted to distinguish BSCE from non-BSCE. The cumulative converted values (gene expression score) of the respective 75 genes from each specimen were obtained and lined up in ascending order to assess the optimal gene expression cut-off score for a definitive diagnosis of BSCE. The validation of this scoring system showed high prediction of the biopsy specimens [area under the curve (AUC)=0.981; 95% confidence interval (CI): 0.952‑1.000] and the commercially available FFPE specimens (AUC=0.901; 95% CI: 0.750-1.000). In conclusion, using CGEA in a gene expression scoring system helps in differentiating BSCE from non-BSCE with high accuracy and may contribute in improving BSCE treatment.

Basaloid squamous cell carcinoma of the esophagus: assessment for high-risk human papillomavirus and related molecular markers

Basaloid squamous cell carcinoma (BSCC) of the esophagus is rare, historically confused for adenoid cystic carcinoma, and recently shown to behave similar to conventional, keratinizing esophageal squamous cell carcinoma. At other sites (eg, oropharynx, anogenital tract) the basaloid phenotype is frequently associated with the presence of high-risk human papillomavirus (HPV). HPVs role in esophageal squamous cell carcinomas is less certain, and to our knowledge, a direct examination of esophageal BSCC for high-risk HPV has not been performed earlier. Nine cases of esophageal BSCC were retrieved from our surgical pathology files. Twenty-two cases of keratinizing esophageal squamous cell carcinoma served as controls. In situ hybridization (ISH) for high-risk HPV and immunohistochemistry for related molecular markers including p53, cyclin D1, and p16 (scored 0 to 4+ based on percentage of cells staining; p53 additionally scored for intensity) were performed. HPV ISH was nonreactive in all tested cases. Compared with controls, BSCC showed less immunoreactivity for p16 and p53 (P=0.003, 0.009). Esophageal BSCC is negative for high-risk HPV by ISH, distinguishing these lesions from other BSCCs. Differential p16 and p53 expression in BSCC suggests that these tumors are molecularly distinct from conventional esophageal squamous cell carcinomas.

Cyclin D1, E2F1 expression levels are associated with characteristics and prognosis of esophageal squamous cell carcinoma

SUMMARY. We performed a multi-institutional analysis of E2F1 and cyclin D1 expression in cases of esophageal squamous cell carcinoma (ESCC). Cyclin D1 and E2F1 are involved in the transition of cell cycle phases and associated with tumor progression. However, no previous studies have concurrently analyzed combined E2F1 and cyclin D1 expression. The purpose of this study was to clarify the relationship of E2F1 and cyclin D1 in ESCC. We studied 122 patients with primary ESCC who underwent surgical tumor resection. Immunohistochemical analyses were performed for E2F1 and cyclin D1. A statistical analysis of immunohistochemistry results, clinicopathological features, and prognosis was performed. E2F1/cyclin D1 (-/-) tumors were present in 31 patients (25.4%) and correlated with reduced tumor progression. In these patients, pT (P=0.0001), pN (P<0.0001), p-Stage (P=0.0019), and survival rates were better than in patients who were positive for either E2F1 or cyclin D1 (P=0.0232). The expression of E2F1 and cyclin D1 is an indicator of tumor progression and prognosis in patients with ESCC. Combined analysis of E2F1 and cyclin D1 expression helps to determine the characteristics and prognosis of ESCC.