Diagnosis and treatment of metanephric adenoma / 中华泌尿外科杂志

ABSTRACT

Objective To explore the clinical and histopathological features of metanephric adenoma (MA). MethodsClinical 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 adenocarcinoma,1 case of chromophobe cell carcinoma,and 1 case of well differentiated 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.