后肾始基腺瘤的诊治

Diagnosis and treatment of metanephric adenoma

目的探讨后肾始基腺瘤（metanephricadenoma，MA）的临床及病理特点。方法对10例MA患者的临床资料进行回顾性分析。本组10例，男4例，女6例。年龄33～65岁，平均45岁。表现为肉眼血尿4例，腰痛2例，查体发现4例。B超检查诊断为肾实性占位9例，肾囊肿1例。CT检查示肾实性占位9例，囊实性1例，10例均有不同程度强化，肿瘤直径2．5～8．0cm，平均4．5cm，诊断为肾癌9例，囊性肾癌1例。行根治性肾切除术9例，肾部分切除术1例。结果病理检查：肿瘤细胞排列成密集的小管状或腺样结构，部分可见乳头状或肾小球样结构，肿瘤与肾组织分界清楚。病理诊断为MA4例，低度恶性MA2例，MA伴恶性成分4例（高分化腺癌2例，嫌色细胞癌1例，高分化乳头状腺癌1例）。7例随访10～34个月，平均22个月，未见复发及转移。结论MA是一种罕见的肾脏良性上皮源性肿瘤，部分可含有恶性成分，少数为恶性，容易误诊为肾癌。保留肾单位手术和根治性肾切除术为主要治疗方法。因其生物学行为不确定，需长期随访。

Objective To explore the clinical and histopathological features of metanephric adenoma （MA）. Methods Clinical and pathological data of 10 cases of MA were analyzed retrospectively. There were 4 males and 6 females, aged from 33 to 65 years, with an average of 45 years. 2 patients had flank pain, 4 patients had gross hematuria, and 4 patients were found by physical examination. The average diameter of tumor was 4.5 cm （2.5 - 8.0 cm）. All patients were diagnosed as renal tumor by CT scan. 9 patients underwent radical nephrectomy and 1 patient underwent partial nephrectomy. Results Pathological examination found that the tumors are composed of densely packed small uniform cells with regular nuclei that formed a tubular or adenoid pattern. Mitotic figures were absent or rare. 4 patients were diagnosed as MA, 2 cases were diagnosed as low-grade malignant MA, and 4 cases were diagnosed as MA with malignant component （2 cases of adenoearcinoma, 1 case of chromophobe cell carcinoma, and 1 case of well differenti- ated papillary adenocarcinoma） , 7 cases were followed up for 22 months （ 10 to 34 months） without recurrence or metastasis. Conclusions MA is very rare benign renal tumor originating from epithelium,and a few are malignant, and some may contain malignant ingredients. Nephron-sparing surgery and radical nephrectomy are eligible for the treatment of MA . Considering the uncertainty of the biological behavior and cellular origin of MA, a long-term follow-up is necessary.