Min K W
Department of Pathology, University of Oklahoma, Oklahoma City 73104.
Am J Surg Pathol. 1992 Feb;16(2):145-55. doi: 10.1097/00000478-199202000-00007.
Microscopic appearances of spindle cell tumors of the gastrointestinal tract are suggestive of smooth muscle origin; however, they usually lack specific muscle cell features by electron microscopy and immunohistochemistry, thus justifying their designation as stromal tumors. The present report describes nine cases of small intestinal stromal tumors with eosinophilic stromal globules composed of tangles of curved fibers with crossbands simulating an appearance of skeins, designated as skeinoid fibers. Patients' ages ranged from 28 to 87 years; and four were male. The tumors presented as well-delineated mural nodules ranging from 1.8 to 13 cm in size, causing intestinal obstruction or hemorrhage. Four were in the duodenum, three in the jejunum, and two unspecified. Microscopically, seven were benign; one, to the largest, was definitely malignant and metastasized to the liver. Another, the second largest (7.5 cm), showed moderate atypia with two mitoses per 10 high-power fields. The light microscopic appearance, including immunohistochemistry, were typical for small intestinal stromal tumors. Skeinoid fibers were strongly periodate-Schiff's procedure-positive and stained blue with the trichrome stain. They appeared as a few micra-sized specks to large globules reaching a few millimeters. Skeinoid fibers were also found in three neurogenic spindle cell tumors (an acoustic neuroma, a neurofibroma, and a plexosarcoma of the mesentery), suggesting that such fibers are possible ultrastructural markers for neurogenic tumors and thus small intestinal stromal tumors with skeinoid fibers are neurogenic in origin.
胃肠道梭形细胞瘤的显微镜下表现提示其起源于平滑肌；然而，通过电子显微镜和免疫组织化学检查，它们通常缺乏特异性的肌细胞特征，因此将其命名为间质瘤是合理的。本报告描述了9例小肠间质瘤，其具有嗜酸性间质小球，由弯曲纤维缠结组成，带有横纹，形似线团，称为类线团纤维。患者年龄在28岁至87岁之间；4例为男性。肿瘤表现为边界清晰的壁内结节，大小从1.8厘米至13厘米不等，可导致肠梗阻或出血。4例位于十二指肠，3例位于空肠，2例部位未明确。显微镜下，7例为良性；最大的1例肯定为恶性，已转移至肝脏。另一例第二大的肿瘤（7.5厘米）显示中度异型性，每10个高倍视野有2个核分裂象。光镜表现，包括免疫组织化学，均为小肠间质瘤的典型表现。类线团纤维对过碘酸-希夫氏染色呈强阳性反应，用三色染色法染成蓝色。它们表现为从几微米大小的斑点到几毫米大小的大球状物。在3例神经源性梭形细胞瘤（1例听神经瘤、1例神经纤维瘤和1例肠系膜丛状肉瘤）中也发现了类线团纤维，提示此类纤维可能是神经源性肿瘤的超微结构标志物，因此具有类线团纤维的小肠间质瘤起源于神经源性。
