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).

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.

References

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• 2 Kudo S. Endoscopic mucosal resection of flat and depressed type of early colorectal cancer.  Endoscopy. 1993;  25 455-461
• 3 Saito K, Arai K, Mori M. p53 overexpression and K-ras codon 12 mutations in submucosal invasive depressed-type colorectal cancer.  Oncol Rep. 2000;  7 741-744
• 4 Kaneko K, Kurahashi T, Makino R. et al . Pathological features and genetic alterations in colorectal carcinomas with characteristics of nonpolypoid growth.  Br J Cancer. 2004;  91 312-318
• 5 Hayakawa M, Shimokawa K, Kusugami K. et al . Clinicopathological features of superficial depressed-type colorectal neoplastic lesions.  Am J Gastroenterol. 1999;  94 944-949