Tomozawa S, Masaki T, Matsuda K, Yokoyama T, Ishida T, Muto T
Department of Surgical Oncology, The University of Tokyo, Japan.
J Gastroenterol. 1998 Dec;33(6):872-5. doi: 10.1007/s005350050191.
A 66-year-old Japanese man had a positive fecal occult blood test at a regular check-up, and a large polypoid mass was detected in the cecum by barium enema study. Colonoscopy showed a submucosal tumor with ulcer protruding into the cecal lumen. A large-forceps biopsy specimen was taken from the bottom of the ulcer. With the tentative diagnosis of neurogenic tumor, ileocecal resection was performed. The tumor showed spindle-cell proliferation in a concentric or fascicular pattern. Immunohistochemically, the tumor cells were diffusely positive for S-100 protein, and they had intracytoplasmic periodic acid Schiff (PAS)-positive crystalloids. The mitosis count was low (about 1 per 20 high-power fields). The pathological diagnosis of this tumor was benign gastrointestinal schwannoma. A large number of schwannoma cases have been reported since 1910 when Verocay reported it as a true tumor that stemmed from Schwann cells and did not contain neuroganglion cells. However, gastrointestinal schwannomas are rare, and schwannomas of the large intestine are extremely rare. We reviewed 40 cases already reported in Japan and this present case in order to clarify the clinicopathological features of this tumor.
一名66岁的日本男性在定期体检时粪便潜血试验呈阳性，钡灌肠检查发现盲肠有一个大的息肉样肿物。结肠镜检查显示一个向盲肠腔内突出的伴有溃疡的黏膜下肿瘤。从溃疡底部取了大块钳取活检标本。初步诊断为神经源性肿瘤后，进行了回盲部切除术。肿瘤表现为呈同心状或束状排列的梭形细胞增殖。免疫组化显示，肿瘤细胞S-100蛋白弥漫性阳性，且有胞质内过碘酸希夫（PAS）阳性结晶。有丝分裂计数较低（每20个高倍视野约1个）。该肿瘤的病理诊断为良性胃肠道神经鞘瘤。自1910年韦罗凯将其报道为一种起源于施万细胞且不含神经节细胞的真性肿瘤以来，已有大量神经鞘瘤病例被报道。然而，胃肠道神经鞘瘤罕见，大肠神经鞘瘤极为罕见。我们回顾了日本已报道的40例病例及本病例，以阐明该肿瘤的临床病理特征。
