Yamada Takahiro, Hisa Takeshi, Shiozawa Satoshi, Kudo Akiharu, Furukawa Ryutaro
Department of Gastroenterology, Saku Central Hospital Advanced Care Center, 3400-28 Nakagomi, Saku, Nagano, 385-0051, Japan.
Clinical Pathology, Saku Central Hospital Advanced Care Center, Nagano, Japan.
J Med Ultrason (2001). 2018 Jan;45(1):175-180. doi: 10.1007/s10396-017-0798-1. Epub 2017 Jun 21.
A 50-year-old man had undergone chemotherapy and radiotherapy for malignant lymphoma 1 year earlier. Follow-up computed tomography revealed a gallbladder polyp. Transabdominal ultrasound demonstrated a 20-mm hypoechoic sessile polyp with basal waist in the gallbladder fundus; the surface was covered with a hyperechoic layer of non-uniform thickness. On contrast-enhanced computed tomography, the polyp showed an early uniform and sustained staining pattern. Magnetic resonance imaging revealed that the polyp had low and slightly high signal intensities on T1- and T2-weighted imaging, respectively. Gallbladder bed resection was performed with the diagnosis of special tumor. Histologically, the polyp comprised a proliferation of myofibroblast-like spindle cells with inflammatory cell infiltration, without muscularis propria or vascular invasion. Most of the polyp surface was covered with necrotic exudate, and part of the normal epithelium remained. Consequently, a diagnosis of inflammatory myofibroblastic tumor was made. The sessile shape with basal waist, epithelium shedding, and surface necrotic exudative matter may represent intraluminal expansive growth such as a subepithelial tumor. A surface with a hyperechoic layer of non-uniform thickness on gallbladder polyp can help in the diagnosis of a tumor with expansive growth directly under the epithelium with stretching/rupture of the epithelium.
一名50岁男性1年前因恶性淋巴瘤接受了化疗和放疗。随访计算机断层扫描发现胆囊息肉。经腹超声显示胆囊底部有一个20毫米的低回声无蒂息肉，有基底腰部；表面覆盖着一层厚度不均匀的高回声层。在增强计算机断层扫描中，息肉呈现早期均匀且持续的强化模式。磁共振成像显示，息肉在T1加权成像和T2加权成像上分别具有低信号强度和略高信号强度。诊断为特殊肿瘤后进行了胆囊床切除术。组织学上，息肉由肌成纤维细胞样梭形细胞增殖并伴有炎性细胞浸润组成，无固有肌层或血管侵犯。息肉表面大部分被坏死渗出物覆盖，部分正常上皮残留。因此，诊断为炎性肌纤维母细胞瘤。有基底腰部的无蒂形状、上皮脱落和表面坏死渗出物可能代表腔内膨胀性生长，如上皮下肿瘤。胆囊息肉表面有一层厚度不均匀的高回声层有助于诊断上皮下直接有膨胀性生长且上皮有拉伸/破裂的肿瘤。
