Clinical characteristics of adult Wilms' tumor

：Objective To investigatethe clinical characteristics of adult Wilms'tumor in Chinese adults and to improve therecognition of adult Wilms'tumor.Methods The clinical data of 6 Wilms'tumor patientstreated in our hospital were reviewed. Of them, there were 4 male patients and 2 femalepatients with mean age of 31 years old. Four patients with abdominal and flank pain and 2patients with abdominal masses were the main clinical manifestations. One case accompaniedwith hematuria and another one had fever.Tumor masses were palpable by physicalexamination in 4 patients. Five patients had percussion tenderness over kidney region and1 case had abdominal tenderness. Six cases underwent urinalysis and red blood cell waspositive in 2 cases. There were no abnormal results in other laboratory tests. Chest X-raywas routinely performed before operation. Six patients underwent ultrasonography and allshowed hypoechoic masses (5.0cm×5.0 cm-22.0 cm×25.0 cm) with clear margin. Four casesexamined by CT and all had solid masses with inhomogeneous density and clear margin. Onenhanced CT scan, 1 of 4 cases demonstrated irregular enhancement of the mass with localhemorrhagic necrosis area. The CT value ranged from 11-40 HU, with an average value of22.5 HU, and increased to 35-78 HU, with an average value of 63.5 HU after administrationof contrast. Two cases of MRI revealed solid mass defects.Three cases underwent IVUexamination and showed the enlargement of renal umbra as well as thinning of renal calicescaused by the compression of tumor and 1 case showed hydronephrosis.Thus, 5 cases werediagnosed with renal tumor and 1 case was diagnosed with cavitas pelvis tumor beforeoperation. Five patients successfully underwent nephrectomies and 1 patient acceptedoophorotomy with no subsequent complication.Retroperitoneal lymph node dissection(RPLND)was performed at the time of radical nephrectomy or oophorotomy in all patients. The tumorwas found to be about 5-25 cm in size during operation. One of the tumors had invadedpancreas tail, one had invaded to the lateral abdominal wall and one had invaded into theinferior caval vein. Renal hilar lymph node was found to be exceeded 1.5 cm×1.5 cm in 2patients. The post-operative incisal surface of the tumor presented with gray-yellowcolor. Capsule was intact in 4 patients. Three cases had hemorrhagic necrosis in tumorcenter. All the specimens sent for the pathological examination. None received adjuvanttherapy before operation. Four patients received chemotherapy plus radiotherapy aftersurgery and other 2 patients received chemotherapy only. All patients were followed upwith routine lab tests, ultrasonography and chest X-ray.Results Six patients were stagedaccording to the National Wilms'Tumor Study staging system as follows: 1 case in stage Ⅰ, 2cases in stageⅡ, 2 cases in stage Ⅲand 1 case instage Ⅳ.Nephrectomies or oophorotomy were performed in all patients successfully. Tumor diameterswere from 4.5-25.0 cm, in average 11.8 cm.All cases had pathological diagnosis of Wilm'stumor. Five cases were classified into favorable histologic type and 1 case was inunfavorable histologic type. Two patients with lymph node metastasis and 3 patients withlocal invasion were observed. One patient with pulmonary metastasis was recorded. Sixpatients were followed up for 1-7 years. Five patients survived with no evidence of cancerrecurrence. One patient died of pulmonary metastasis 2 years after surgery.Conclusions Themajority of adult Wilms'tumors are found with local invasion and metastasis. The incidenceof hematogenous metastasis in adult Wilms'tumor is higher than other types of renal tumoras well. The early diagnosis and radical surgical treatment and adjuvant chemoradiotherapycould improve the survival rate. Key words: Wilms tumor; Clinical characteristics; Adult