title: Esophageal early basaloid squamous carcinoma with unusual narrowband imaging magnified endoscopy findings.
abstract: Basaloid squamous carcinoma (BSC) is a rare variant of esophageal cancer. There are very few reports of "early" BSC. Here we report a case of early BSC with unusual findings by narrowband imaging magnified endoscopy (NBI-ME). A 70-year-old man with a middle thoracic esophageal tumor was referred to our hospital. White-light endoscopy revealed a reddish depressed lesion 5 mm in diameter having a subepithelial tumor-like prominence with a gentle rising slope. NBI-ME revealed irregular loop-shaped microvessels coexistent with thick irregularly branched non-looped vessels. Iodine staining revealed a pale brown lesion. We performed endoscopic submucosal dissection for diagnostic treatment. Histologic examination showed the proliferation of basal cell-like hyperchromatic tumor cells in the lamina propria and with slight invasion into the submucosa at a depth of 320 μm. The tumor cells formed solid nests and microcystic structures, containing an Alcian blue-positive mucoid matrix. The surface was covered with squamous epithelium without cellular atypia. Thin vessels were observed in the intra-epithelial papilla and thick vessels were observed around the solid nests beneath the epithelium. Based on these findings together, we diagnosed the lesion as BSC. In this case, the NBI-ME findings differed from those of typical squamous cell carcinoma in that both non-invasive cancer-like irregular loop-shaped microvessels coexisted with massively invasive cancer-like thick non-looped vessels. We speculate that the looped and non-looped vessels observed by NBI-ME histologically corresponded to thin vessels in the intra-epithelial papilla and thick vessels around the tumor nests, respectively. These NBI-ME findings might be a feature of early esophageal BSC.
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Yugo
authors.initials: Y
authors.lastname: Kai
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Motohiko
authors.initials: M
authors.lastname: Kato
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Akasaka
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Shinzaki
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishida
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tsujii
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Morii
authors.affiliation: Yugo Kai, Motohiko Kato, Yoshito Hayashi, Tomofumi Akasaka, Shinichiro Shinzaki, Tsutomu Nishida, Masahiko Tsujii, Tetsuo Takehara, Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Takehara
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000098:blood supply* / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D004210:Dissection / Q000379:methods; D055088:Early Detection of Cancer; D004938:Esophageal Neoplasms / Q000098:blood supply* / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D000077277:Esophageal Squamous Cell Carcinoma; D004945:Esophagoscopy / Q000379:methods*; D006801:Humans; D007089:Image Enhancement; D007150:Immunohistochemistry; D008297:Male; D055806:Microvessels / Q000737:chemistry / Q000473:pathology*; D062048:Narrow Band Imaging; D011237:Predictive Value of Tests; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor
keywords: Basaloid squamous carcinoma; Endoscopic submucosal dissection; Esophagus; Narrowband imaging