Electron microscopic and immunohistochemical studies of gastrointestinal stromal tumors.
Sixteen gastrointestinal stromal tumors (GISTs) were studied by immunohistochemical analysis and an ultrastructural procedure. The tumor locations were as follows: esophagus (2), stomach (7), small intestine (3), and large intestine (4). Four of the lesions were classified as malignant, 2 as borderline, and 10 as benign. On the basis of the immunohistochemical analysis, the tumors were classified as follows: 1 as myogenic type, 2 as Schwann cell type, 8 as Cajal cell type (including 2 gastrointestinal autonomic nerve tumors, GANTs), and 5 as mixed-cell type. In each subtype the phenotype was compared to the ultrastructural findings. Myogenic and Schwann cell type revealed ultrastructurally smooth muscle differentiation and schwannian tumor. All 8 tumors of the Cajal cell type revealed interdigitating cytoplasmic processes with occasional clusters of filopodia. Two tumors were subdivided as GANT. Five tumors of mixed-cell type were composed of a mixture of cells with variable myogenic features or variable neural differentiation. We confirmed in this study that immunohistochemical analysis reflected electron microscopic findings.
Yamaguchi
J.
J
Department of Pathology, Obihiro Kosei General Hospital, Minami 8-chome, Nishi 6-jo, Obihiro 080-0016, Japan.
Sawada
Norimasa
N
Tobioka
Hirotoshi
H
Takakuwa
Reiko
R
Goto
Tomoko
T
Sakuma
Yuji
Y
Ikeda
Tatsuru
T
Satoh
Masaaki
M
Mori
Michio
M