Abstract：
BACKGROUND: Renal Osseous Metaplasia (OM) is a rare condition in which mature bone forms within the renal parenchyma, typically as focal cortical lesions. Although it is usually considered a spontaneous and less pathologically significant lesion, it has been observed in damaged renal allografts and other urinary tract sites. The case we present involves a native kidney with a simple renal cyst, where histopathological examination post-tumor enucleation revealed OM, emphasizing its noteworthy presence in clinical settings.
METHODS: A 37-year-old female with a history of cesarean delivery and recent emergency surgery presented with abdominal and left flank pain. Initial ultrasound revealed a 4.2 cm anechoic cyst in the lower pole of the left kidney, which was confirmed by abdominal computed tomography (CT-scan as a well-defined fluid density cyst with a thick calcified wall. Surgical enucleoresection identified a Stoney hard mass with a unilocular cyst, histopathologically diagnosed as a simple renal cyst with metaplastic bone and hematopoietic elements. The patient had an uneventful postoperative course and remained well during the follow-up.
CONCLUSIONS: Osseous metaplasia (OM) involves extraskeletal bone formation and is associated with factors such as chronic ischemia and inflammation. While rare in renal pathology, it occurs in native kidneys, damaged renal allografts, and the urinary tract, posing radiological challenges in differentiating it from calcification. Accurate diagnosis requires histopathological examination because of the difficulties in distinguishing OM from calcification on imaging studies.
CONCLUSIONS: This case revealed Osseous Metaplasia in a simple cyst of the native kidney, urging vigilance in the diagnosis. While generally benign, its occurrence in damaged renal areas emphasizes its clinical significance, prompting further research. Heightened awareness and thorough examination are crucial for accurate diagnosis and patient management.
METHODS: A 37-year-old female with a history of cesarean delivery and recent emergency surgery presented with abdominal and left flank pain. Initial ultrasound revealed a 4.2 cm anechoic cyst in the lower pole of the left kidney, which was confirmed by abdominal computed tomography (CT-scan as a well-defined fluid density cyst with a thick calcified wall. Surgical enucleoresection identified a Stoney hard mass with a unilocular cyst, histopathologically diagnosed as a simple renal cyst with metaplastic bone and hematopoietic elements. The patient had an uneventful postoperative course and remained well during the follow-up.
CONCLUSIONS: Osseous metaplasia (OM) involves extraskeletal bone formation and is associated with factors such as chronic ischemia and inflammation. While rare in renal pathology, it occurs in native kidneys, damaged renal allografts, and the urinary tract, posing radiological challenges in differentiating it from calcification. Accurate diagnosis requires histopathological examination because of the difficulties in distinguishing OM from calcification on imaging studies.
CONCLUSIONS: This case revealed Osseous Metaplasia in a simple cyst of the native kidney, urging vigilance in the diagnosis. While generally benign, its occurrence in damaged renal areas emphasizes its clinical significance, prompting further research. Heightened awareness and thorough examination are crucial for accurate diagnosis and patient management.
摘要：
背景：肾骨上皮化生（OM）是一种罕见的疾病，其中成熟的骨在肾实质内形成，通常作为局灶性皮质病变。尽管它通常被认为是自发性和病理意义较小的病变，在受损的肾脏同种异体移植物和其他泌尿道部位观察到了这种情况。我们介绍的病例涉及一个带有单纯性肾囊肿的天然肾脏，肿瘤摘除术后的组织病理学检查显示OM，强调其在临床环境中值得注意的存在。
方法：一名37岁女性，有剖宫产史，近期急诊手术，表现为腹部和左侧腹疼痛。最初的超声显示左肾下极有一个4.2厘米的无回声囊肿，通过腹部计算机断层扫描（CT扫描为明确的流体密度囊肿，钙化壁较厚。手术核苷酸切除发现了具有单眼囊肿的Stoney硬块，组织病理学诊断为单纯性肾囊肿，伴有化生骨和造血元素。患者术后病程顺利，随访期间保持良好。
结论：骨化生（OM）涉及骨骼外骨形成，并与慢性缺血和炎症等因素有关。虽然在肾脏病理学中很少见，它发生在天然的肾脏，受损的肾同种异体移植物，和泌尿道，在区分钙化方面提出了放射学挑战。准确的诊断需要组织病理学检查，因为在影像学研究中难以区分OM和钙化。
结论：此病例显示单纯肾囊肿中的骨上皮化生，敦促在诊断中保持警惕。虽然通常是良性的，其在受损肾脏区域的发生强调了其临床意义，促使进一步研究。提高意识和全面检查对于准确诊断和患者管理至关重要。
方法：一名37岁女性，有剖宫产史，近期急诊手术，表现为腹部和左侧腹疼痛。最初的超声显示左肾下极有一个4.2厘米的无回声囊肿，通过腹部计算机断层扫描（CT扫描为明确的流体密度囊肿，钙化壁较厚。手术核苷酸切除发现了具有单眼囊肿的Stoney硬块，组织病理学诊断为单纯性肾囊肿，伴有化生骨和造血元素。患者术后病程顺利，随访期间保持良好。
结论：骨化生（OM）涉及骨骼外骨形成，并与慢性缺血和炎症等因素有关。虽然在肾脏病理学中很少见，它发生在天然的肾脏，受损的肾同种异体移植物，和泌尿道，在区分钙化方面提出了放射学挑战。准确的诊断需要组织病理学检查，因为在影像学研究中难以区分OM和钙化。
结论：此病例显示单纯肾囊肿中的骨上皮化生，敦促在诊断中保持警惕。虽然通常是良性的，其在受损肾脏区域的发生强调了其临床意义，促使进一步研究。提高意识和全面检查对于准确诊断和患者管理至关重要。
