Departments of Pathology, Immunology, and Laboratory Medicine.
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA.
Am J Surg Pathol. 2022 Sep 1;46(9):1234-1240. doi: 10.1097/PAS.0000000000001901. Epub 2022 Apr 8.
Radioembolization therapy utilizes yttrium-90 (Y90) impregnated resin (SIR-Spheres) or glass (TheraSpheres) microspheres to selectively target hepatic lesions via transarterial radioembolization. Occasional cases of gastrointestinal tract injury, secondary to nontargeted delivery of microspheres, have been reported, but large descriptive pathology series are lacking. We identified 20 cases of histologically confirmed mucosal injury associated with Y90 from 17 patients and assessed the corresponding clinical and pathologic sequelae. The mucosal biopsies were obtained from 1 to 88 months following Y90 therapy (median: 5 mo). Most cases were gastric (17, 85%), while the remaining were duodenal. Endoscopic ulceration was seen in the majority of cases (16, 80%), and mucosal erythema in the remaining 4. Histologically, a majority (19, 95%) of cases showed rounded, dark blue to purple microspheres measuring 4 to 30 µm, consistent with resin microspheres. A single case with glass microspheres demonstrated 26 µm translucent beads. Histologic evidence of ulceration was appreciated in 14 (70%) cases, and the microspheres were clearly intravascular in 6 (30%). A foreign body giant cell reaction to the microspheres was uncommon (3 cases, 15%). We additionally performed a retrospective review of all gastrointestinal tissue obtained postprocedure from 784 sequential patients treated with Y90 microspheres. Three patients (0.4%) demonstrated the presence of resin microspheres upon histologic examination. No cases involving glass-based Y90 were identified ( P =0.0078), despite the majority of patients having received glass radioembolization (630, 80%). This increased risk of secondary sphere dissemination is likely related to the increased number of particles required per activity for resin versus glass microspheres. We conclude that Y90 microspheres may be encountered in the gastrointestinal tract years after initial liver-targeted therapy and, when present, are often associated with mucosal ulceration. This finding is less likely to be encountered in patients who received Y90 radioembolization utilizing glass microspheres.
钇 90（Y90）载药树脂微球（SIR-Spheres）或玻璃微球（TheraSpheres）经动脉栓塞选择性靶向治疗肝脏病变。偶尔有报道称，由于非靶向递送微球导致胃肠道损伤，但缺乏大型描述性病理学系列。我们从 17 名患者中确定了 20 例经组织学证实的与 Y90 相关的黏膜损伤，并评估了相应的临床和病理后果。黏膜活检在 Y90 治疗后 1 至 88 个月获得（中位数：5 个月）。大多数病例为胃（17 例，85%），其余为十二指肠。大多数病例（16 例，80%）可见内镜下溃疡，其余 4 例可见黏膜红斑。组织学上，大多数（19 例，95%）病例显示直径为 4 至 30μm 的圆形、深蓝色至紫色微球，符合树脂微球。一例玻璃微球显示 26μm 半透明珠。14 例（70%）病例可见溃疡组织学证据，6 例（30%）微球明确位于血管内。微球周围异物巨细胞反应少见（3 例，15%）。我们还对 784 例连续接受 Y90 微球治疗的患者的所有胃肠道组织进行了回顾性复习。3 例（0.4%）患者的组织学检查发现有树脂微球。尽管大多数患者接受了玻璃放射性栓塞（630 例，80%），但没有发现涉及玻璃基 Y90 的病例（P=0.0078）。与玻璃微球相比，树脂微球每单位活性所需的颗粒数量增加，导致继发球体扩散的风险增加。我们得出结论，Y90 微球在初始肝靶向治疗后数年可能会在胃肠道中遇到，并且当存在时，通常与黏膜溃疡有关。在接受玻璃微球 Y90 放射性栓塞治疗的患者中，这种发现不太可能出现。
