Inflammatory myofibroblastic tumor of the gallbladder: a case report and literature review

Abstract

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.

Gallbladder polyps: Correlation of size and clinicopathologic characteristics based on updated definitions

“…For the non-neoplastic group, in addition to well-recognized cholesterol polyps, mucosal injury polyps, including fibromyoglandular polyps were recognized [4]. A variety of other polyp types such as inflammatory fibroid polyp and others were discovered to occur in this organ [5,6]. For the neoplastic polyps, which were regarded in various different categories (i.e., pyloric gland adenoma, biliary adenoma, intestinal adenoma, tubular adenoma, tubulopapillary adenoma, papillary adenoma, papillary neoplasm, and papillary carcinoma) [7] are now collected under two headings in the WHO 2019 classification as "intracholecystic papillary neoplasms" (for the papillary examples) and "pyloric gland adenomas" (for the tubular ones with pyloric type glands) [8].…”

Inflammatory Myofibroblastic Tumor of Gallbladder Mimicking Gallbladder Cancer: A Case Report

“…Therefore, it is difficult to differentiate from other types of tumors and inflammatory conditions. Most of the reported primary gallbladder IMT showed gallbladder wall thickening with or without invasion of the liver parenchyma on radiologic examinations and were thus initially misdiagnosed as advanced gallbladder cancer or severe cholecystitis (2,3,10,11).…”

Anaplastic lymphoma kinase-positive inflammatory myofibroblastic tumor of the breast: a case report and review of the literature

“…Distant metastasis of IMT is extremely rare, occurring in < 5% of cases [ 26 ]. A report in Japan described rapid enlargement of a low-grade malignant spindle cell tumor within 1 year [ 39 ]. Rare malignant transformation after complete resection has also been reported [ 27 ].…”

“…Although IMT is usually cured by resection with a large enough margin, it can sometimes show rapid growth, infiltration, recurrence, and metastasis [ 25 , 39 ]. Despite their serious complications, ALK inhibitors have shown high response rates in patients with ALK-positive lung cancer worldwide.…”