UNASSIGNED: Renal epidermoid cysts are extremely rare, with only 12 cases reported in the literature. Their radiographic features often resemble cystic renal cell carcinoma, frequently prompting unnecessary nephrectomy. A 64-year-old man with a history of nephrolithiasis presented with left flank pain and hematuria. Imaging revealed a complex cystic renal mass suspicious for renal cell carcinoma. Following left radical nephrectomy, histopathology examination revealed a benign epidermoid cyst. Renal presentation of epidermoid cyst poses unique diagnostic and therapeutic challenges. Possible pathogenesis includes ectopic epidermal implantation during embryogenesis or squamous metaplasia following chronic irritation or deficiency. Radiographic distinction from concerning entities like renal cell carcinoma is difficult but imperative to avoid extensive surgery. This case highlights the diagnostic pitfalls and management considerations for renal epidermoid cysts. Additional study of clinical and imaging factors that distinguish epidermoid cysts from renal cell carcinoma can guide conservative management when appropriate, avoiding unnecessary nephrectomy for benign disease.
■肾表皮样囊肿极为罕见,文献中只有12例报道。他们的影像学特征通常类似于囊性肾细胞癌,经常提示不必要的肾切除术。一名有肾结石病史的64岁男子,表现为左侧腹疼痛和血尿。影像学检查显示一个复杂的囊性肾脏肿块,可疑为肾细胞癌。左根治性肾切除术后,组织病理学检查发现良性表皮样囊肿。表皮样囊肿的肾脏表现提出了独特的诊断和治疗挑战。可能的发病机制包括胚胎发育过程中的异位表皮植入或慢性刺激或缺乏后鳞状上皮化生。影像学上与肾细胞癌等相关实体的区别很困难,但必须避免进行广泛的手术。此病例突出了肾表皮样囊肿的诊断陷阱和管理注意事项。对表皮样囊肿和肾细胞癌的临床和影像学因素的进一步研究可以在适当的时候指导保守治疗,避免良性疾病不必要的肾切除术。