Pediatric Urology Department. Hospital de Pediatria Pr, Dr Juan P Garrahan, Buenos Aires, Argentina.
Pathology Department. Hospital de Pediatria Pr, Dr Juan P Garrahan, Buenos Aires, Argentina.
Pediatr Transplant. 2021 Dec;25(8):e14109. doi: 10.1111/petr.14109. Epub 2021 Aug 6.
Epstein-Barr virus (EBV) is a DNA virus with oncogenic potential, especially in immunocompromised patients. EBV can promote smooth muscle proliferation, resulting in EBV-associated smooth muscle tumors (EBV-SMT).
We report a case of a 10-year-old child with end-stage renal disease secondary to hypoplastic crossed and fused kidneys who underwent kidney transplantation. EBV serology was unknown for the donor and negative for the recipient; three months after he had a primary EBV infection. Two years after the transplantation, percutaneous nephrostomy was performed because of a drop in the estimated glomerular filtration rate and severe dilatation of the graft. Nephrography showed contrast enhancement of the pelvis of the graft kidney and proximal ureter, with a clear blockage at the level of the mid ureter and no passage towards the bladder. A 1.5-cm tumor was found causing intraluminal compression of the mid ureter.
Complete resection of the tumor and distal ureter was performed leaving a short proximal ureter. A tension-free uretero-ureteroanastomoses was achieved using the native ureter. There were no surgical complications. Histologic evaluation showed spindle-shaped muscle cells, moderate pleomorphism, and inflammatory infiltration. Immunohistochemical staining was positive for muscle-specific actin. Epstein-Barr encoding region (EBER) in situ hybridization was positive, confirming the diagnosis of EBV-associated SMT.
EBV-SMT is an exceedingly rare oncological entity that may develop in either the graft or any other organ. The clinical findings are location related. EBV seroconversion following transplantation might be a risk factor for the development of SMT in solid organ recipients.
EB 病毒（EBV）是一种具有致癌潜能的 DNA 病毒，尤其在免疫功能低下的患者中。EBV 可促进平滑肌增殖，导致 EBV 相关平滑肌肿瘤（EBV-SMT）。
我们报告了一例 10 岁儿童病例，该儿童患有继发于发育不良的交叉融合肾的终末期肾病，接受了肾移植。供体的 EBV 血清学结果未知，受体 EBV 血清学为阴性；在发生原发性 EBV 感染后 3 个月。移植后 2 年，因估计肾小球滤过率下降和移植肾严重扩张而行经皮肾造口术。尿路造影显示移植肾肾盂和近端输尿管对比增强，在输尿管中段有明显梗阻，没有向膀胱的通道。发现一个 1.5 厘米的肿瘤导致输尿管中段腔内受压。
肿瘤和远端输尿管完全切除，留下短的近端输尿管。使用固有输尿管进行无张力输尿管-输尿管吻合术。无手术并发症。组织学评估显示梭形平滑肌细胞，中度多形性和炎症浸润。免疫组织化学染色肌特异性肌动蛋白阳性。EBV 编码区（EBER）原位杂交阳性，证实诊断为 EBV 相关 SMT。
EBV-SMT 是一种非常罕见的肿瘤实体，可能发生在移植物或任何其他器官中。临床表现与部位有关。移植后 EBV 血清学转换可能是实体器官受者发生 SMT 的危险因素。
