Depressed-type early adenocarcinoma of the terminal ileum

Depressed-type neoplasm of the jejunum and the ileum has not yet been recognized. To the best of our knowledge, this is the first case of depressed-type primary adenocarcinoma of the ileum. A 62-year-old man underwent total colonoscopy. A small reddish depressed lesion with marginal elevation, 5 mm in diameter, was detected in the terminal ileum ([ Fig. 1 a ]). A chromoendoscopic view with indigo carmine dye showed a star-shaped demarcation line of the depressed lesion ([ Fig. 1 b ]). A magnifying endoscopic view with crystal violet staining showed small round and tubular pit patterns ([ Fig. 1 c ]). With these findings, we diagnosed intramucosal neoplasm. Fig. 1 a Conventional endoscopic view showed a shallow depressed lesion in the terminal ileum. b Chromoendoscopic view with indigo carmine dye showed a star-shaped demarcation line of the depressed lesion. c Magnifying endoscopic view with crystal violet staining showed regular arrangement of small round and tubular pit patterns. An endoscopic mucosal resection was performed, and the resected lesion measured 5 × 4 mm. Stereomicroscopic view showed a star-shaped, depressed lesion with marginal elevation ([ Fig. 2 a ]). A histopathologic cross section revealed an intramucosal depressed neoplasm with lamina propria invasion ([ Fig. 2 b ]). A high-power view revealed well-differentiated adenocarcinoma ([ Fig. 2 c ]). Cancer-cell nuclei were positive in p53 immunohistochemical staining. A polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) study of p53 genes revealed some mutations of exon 6, 7, and 8. K-ras codon 12 mutations (PCR-restriction fragment length polymorphism [RFLP]) were not observed. Fig. 2 a Stereomicroscopic view showed a star-shaped depressed lesion with marginal elevation. b Histopathologic cross section revealed an intramucosal depressed neoplasm with lamina propria invasion (H & E, original magnification × 10). c High-power view revealed well-differentiated adenocarcinoma (H&E, original magnification × 200). Quality: mobile 360 480 720 Download Video 1 Video clip shows conventional and magnifying endoscopic features of depressed type adenocarcinoma of the terminal ileum, and procedure of endoscopic mucosal resection. Morphological appearance was classified as type 0-IIc in the Paris endoscopic classification [ 1 ], and mimicked a depressed-type colorectal cancer advocated by Kudo [ 2 ]. It had been reported that K-ras mutations were absent in depressed-type colorectal cancers [ 3 ] [ 4 ]. It was reported that rates of p53 positivity in depressed-type colorectal neoplastic lesions were higher in carcinomas and high-grade neoplasms than in low-grade neoplasms [ 5 ]. Therefore the characterizations of the genetic change, such as p53 and K-ras, were mimicking depressed-type colorectal cancer.