Wilms tumor in an adult patient: case report

Nephroblastoma or Wilms tumor is the most common renal neoplasia in children, representing 1/5 of the malignant tumors in this group. Nevertheless, the incidence of such tumor in adults is much rarer with less than 250 cases reported. Due to the low-frequency of this pathology in adults there is not a world widely accepted treatment modality. Currently, the therapeutic options derive from the National Wilms Tumor Study (NWTS). We report a new case with the radiological images, histologic findings, outcomes and follow-up.     

Adult Wilms tumor: a case of prolonged survival achieved by multimodal treatment

Wilms tumor is one of the most common malignant neoplasms in children. In the last 2 decades the survival rate of children with this disease has dramatically increased. However, in adults, the guideline for its management is less clear. We herein report the prolonged survival of a patient with advanced adult Wilms tumor after treatment with chemotherapy, irradiation and operations. Adult Wilms tumor should be treated aggressively with a well-timed combination of surgery, chemotherapy and radiotherapy (i.e., multimodal treatment), even if the stage of the disease was advanced. Thereby, we suspect that the prognosis of adult Wilms tumor would be markedly improved.     

成人肾母细胞瘤的诊疗及预后分析（附10例报告）

目的：探讨成人肾母细胞瘤的诊疗方法和预后。方法：回顾性分析10例成人肾母细胞瘤患者的临床资料。男8例,女2例,年龄16～62岁,平均29岁。就诊症状为单纯肉眼血尿3例、腰腹部肿块或腰腹痛4例（伴血尿2例）、无症状查体发现3例。患者均行B超、IVU、尿脱落细胞学检查,8例行CT平扫＋强化检查。影像学检查提示肾占位6例、肾盂占位3例、输尿管占位1例。CT提示肾门或腹腔淋巴结肿大4例。10例均行手术治疗,根治性肾切除6例,患肾、输尿管全段切除＋膀胱输尿管口袖口状切除4例,2例根治性肾切除患者因肿物与周围粘连严重切除部分腹膜。行腹膜后淋巴结清扫5例。结果：所有病例均于术后病理确诊为肾母细胞瘤,预后良好组织型（FH）4例,预后不良组织型（UH）6例,病理证实淋巴结转移3例。按美国国家肾母细胞瘤研究组（NWTS）分期标准,分别为Ⅰ期4例、Ⅱ期3例、Ⅲ期3例。7例患者接受术后辅助放化疗。随访9例患者1～13年,5例无瘤生存,生存时间为1．5～13年,平均4．4年。1例术后1年死于肿瘤肺转移,1例术后1年死于肿瘤脑转移,2例术后2年内局部复发,再次接受手术。结论：成人肾母细胞瘤为罕见的恶性肿瘤,预后较差,确诊主要依靠病理诊断,目前尚无公认的最佳治疗手段。手术治疗并辅以合理、及时的放疗、化疗是改善其预后的有效措施。     

Wilms tumor in adults

Wilms tumor rarely occurs during adult life. We have found 197 such cases reported in the world literature. However, there are some controversies whether all of these are true Wilms tumors or rather a variety of adenocarcinomas or sarcomatoid renal cell carcinoma. We report here 2 additional cases of well-documented Wilms tumors in adults.     

RENAL ANGIOMYOLIPOMA IN CHILDREN: DIAGNOSTIC DIFFICULTY IN 3 PATIENTS

Purpose

Because angiomyolipoma is less common in children than in adults, its diagnosis can be difficult. We present 3 cases of pediatric angiomyolipoma in which diagnostic problems resulted due to the presenting characteristics.

Materials and Methods

We report on 3 children with unilateral renal angiomyolipoma. Computerized tomography (CT) and ultrasonography revealed 3 large renal masses, 20, 7 and 8 cm. in diameter, respectively. A correct diagnosis was not made preoperatively in any case by CT, ultrasound or fine needle biopsy. Wilms tumor was suspected in the first patient who received preoperative chemotherapy. Imaging was inconclusive in the other 2 cases.

Results

All patients underwent surgical exploration and subsequent nephrectomy due to the large size of the tumor. At followup 33, 23 and 13 months postoperatively all children were well without signs of recurrence.

Conclusions

It has been reported that the demonstration of fat on renal ultrasound and CT can diagnose angiomyolipoma in 95% of the cases. Most radiologists rely solely on CT demonstration of lipid density in the renal mass to diagnose angiomyolipoma but the identification at imaging of lipid tissue may be difficult in small tumors. In our cases the fat content of the tumors was less than 10% despite the large size. This low fat content results in misdiagnosis, since fatty tissue is also present in other renal tumors, such as lipoma, liposarcoma, teratoma and Wilms tumors. We recommend conservative surgery when tumor size permits in pediatric patients with angiomyolipoma to avoid chemotherapy.     

Primary renal neuroblastoma--a clinical pathologic study of 8 cases

Neuroblastoma is the most common extracranial solid tumor to occur during infancy and early childhood. However, primary renal neuroblastoma is rare, and only scattered case reports exist in the English medical literature. We report 8 cases that accumulated at our institution over the past 15 years and summarize their clinicopathologic features. The composite picture of a patient with renal neuroblastoma is that of a boy of 17 months of age, who presented with a large renal mass, about 9 cm in size, accompanied by hypertension. The mass was typically hemorrhagic, either encapsulated or unencapsuated, and infiltrating. A renal neuroblastoma can be undifferentiated, poorly differentiated, or differentiating; it falls into either the favorable or the unfavorable histology category, and presentation at higher stages is the rule. The N-myc is usually unamplified, and the bone marrow is usually not involved at presentation. Unless the tumor is undifferentiated or very poorly differentiated, patients with renal neuroblastoma fare well, although not without new and improved modalities of treatment. Primary renal neuroblastoma is perhaps more common than people realize; a higher level of awareness and early recognition are important for its prognosis and management, as they are very different from Wilms tumor.     

Extrarenal Teratoid Wilms’ Tumor in Association with Horseshoe Kidney

Extrarenal teratoid Wilms’ tumor is a rare variant of Wilms’ tumor. Literature shows only 17 reported cases. We present this right-sided teratoid Wilms’ tumor in a 3-year-old boy for its rarity in association with the horseshoe kidney. The tumor was found in the anterior aspect of the right kidney and consisted of triphasic Wilms’ tumor element along with the presence of heterologous components.     

Wilms tumor in adolescence.

A review of the literature reveals that Wilms tumor is rare in adolescence. At the time of diagnosis 78 per cent of children are less than 5 years old. Of 17 cases of Wilms tumor seen at the Ontario Cancer Foundation Clinic in Kingston from 1973 to 1975, 3 children were between 16 and 17 years old. Of 316 cases registered in Ontario with the Ontario Cancer Treatment and Research Foundation only 5 were in the 15 to 19-year age group. The possibility of Wilms tumor in patients beyond the usual age group is not considered as a differential diagnosis because of its relative rarity. Patients may present with features suggestive of neuroblastoma, renal cell carcinoma, hydronephrosis, cholecystitis, appendicitis and twisted ovarian cyst as seen in our 3 patients. In comparison, a review of 84 reported cases of renal cell carcinoma in children from 1934 to 1974 showed 5 cases in the 15 to 18-year age group.     

Distinct features of teratoid Wilms tumor

Teratoid Wilms tumor is an unusual variant of nephroblastoma in which heterologous tissue predominates. Typically, histopathologic examination shows a mixture of mature squamous and mucus-producing columnar epithelium and a prominent component of mature adipose tissue. The treatment of this tumor has not been established because of its rarity with some reports doubting the value of chemotherapy. We report 3 new cases and review the 23 previously reported cases that we were able to identify. The first case was a 2-year-old boy with a huge tumor that occupied most of the abdominal cavity. The second case was a 5-year-old girl with a metastatic tumor in association with horseshoe kidney and is the first case of teratoid Wilms tumor with brain metastasis. The third case was an 11-month-old girl with bilateral involvement. Imaging studies of our patients were similar to those reported in the literature with areas of fat attenuation and calcification. Failure to respond to preoperative chemotherapy was seen in our patients and in most previously reported cases that were treated with preoperative chemotherapy. We recommend treating this entity with protocols designed for Wilms tumor and to conduct further basic research to understand its biologic nature.     

Congenital mesoblastic nephroma

For more than a decade congenital mesoblastic nephroma of infancy has been recognized as an entity different from Wilms tumor in its clinical and histopathologic features. However, this tumor is sometimes confused with Wilms tumor and consequently, inadvertent and vigorous therapy compatible with that for Wilms tumor is given. We reviewed the literature and analyzed 90 cases of congenital mesoblastic nephroma in the English and Japanese literature. The importance of early and accurate histopathologic diagnosis of the resected specimen to avoid inappropriate postoperative therapy is emphasized, and the peculiar features of congenital mesoblastic nephroma are characterized.     

Renal leiomyoma in a child: a rare renal tumor

Renal leiomyoma is a rare benign smooth muscle tumor of the kidney. Most cases are reported in adults, with very few cases described in children. We report a case of right renal leiomyoma in a 6-year-old boy which was suspected of being a Wilms tumor. Contrast-enhanced computed tomography could not differentiate leiomyoma in the kidney, and the mass was diagnosed as a Wilms tumor. Right radical nephrectomy was performed. Diagnosis of renal leiomyoma could only be achieved after histopathologic examination and immunohistochemistry. We recommend that total nephrectomy has to be done in most cases of pediatric renal tumors to avoid the risk of malignancy. There may be a role for nephron sparing surgery, provided the tumor is small, and one has a strong suspicion for the lesion being benign.     

Nephrogenic rests in Wilms tumor patients with the Drash syndrome.

The histological specimens from 12 patients with the Drash syndrome were identified from the National Wilms Tumor Study Group and reviewed for the presence of nephrogenic rests. Of 7 patients with the complete Drash syndrome 6 were evaluable for nephrogenic rests, including 5 (83%) who demonstrated intralobar nephrogenic rests. Of 5 (80%) partial Drash syndrome cases 4 (80%) were also intralobar nephrogenic rest positive. Neither group had perilobar nephrogenic rests identified. In a control population of Wilms tumor patients without the Drash syndrome only 39 of 274 (14%) with unilateral tumor had intralobar nephrogenic rests identified, whereas 26 of 92 (28%) bilateral cases had intralobar nephrogenic rests. There was a significantly higher rate of intralobar nephrogenic rests in complete and partial Drash syndrome cases than in the general Wilms tumor population (p less than 0.001). Wilms tumor patients with intralobar nephrogenic rests and the Drash syndrome present at a younger age and have a higher rate of bilaterality than rest negative Wilms tumor patients. The strong association of intralobar nephrogenic rests in the Drash syndrome approaches that found in the aniridia complex. However, in other syndromes associated with Wilms tumor, such as the Beckwith-Wiedemann syndrome and hemihypertrophy, there is a high prevalence of perilobar nephrogenic rests. In view of the high incidence of intralobar nephrogenic rests in complete and partial Drash syndrome patients, it is probable that events leading to Wilms tumor in patients with the Drash syndrome occur at an early stage in nephrogenesis.     

Pelvic osteoid osteoma in a skeletally mature female

Osteoid osteoma is the most common bone-producing tumor that typically presents with "throbbing night pain" and that improves dramatically with use of low-dose salicylates. Few cases of pelvic osteoid osteoma have been reported, and most have involved patients younger than age 30. Surgical excision classically has been the treatment of choice, but, recently, less invasive modalities, including radiofrequency ablation, have begun to supplant surgical management of osteoid osteoma, resulting in a decrease in the need for definitive surgical diagnosis and treatment. We present a rare case of osteoid osteoma in the pelvis of a woman older than age 30.     

Extrarenal Wilms tumor in children with unfavorable histology: a case report

Extrarenal Wilms tumor is extremely rare, and only 25 cases in children have been reported to date in Japan. A 2-year-old girl presented with a large left lower quadrant abdominal mass. Abdominal computed tomography revealed a retroperitoneal tumor located below the left kidney. At laparotomy, the tumor was encapsulated without evidence of metastasis to other abdominal organs. Pathologic diagnosis of the tumor was extrarenal Wilms tumor with diffuse anaplasia. After complete tumor resection, chemotherapy was administered according to the treatment protocol (Regimen I) of the Japan Wilms Tumor Study Group. Cyclophosphamide and etoposide were administered in combination with vincristine and doxorubicin. Two years after treatment, the patient has had no evidence of recurrence.     

Wilms-Tumoren im Erwachsenenalter

Wilms’ tumors develop from persistent, primitive metanephrogenic stem cells. Their biology and etiology in adults is still unknown even though remnants of primitive metanephrogenic tissue, which tends to malignancy, is suspected, and there are very few scientific studies on the biology of Wilms’ tumors in adults. Such a tumor occurs at a rate of 0.2/million adults in Europe and the USA. In this article, we describe the course of the disease in two adults with histologically confirmed Wilms’ tumors. Both patients underwent a radical nephrectomy followed by chemotherapy as indicated by the SIOP nephroblastoma study.     

Renal cell carcinoma in children.

Six cases of renal cell carcinoma in children between seven and nineteen years of age are reported. These patients differ from those with Wilms tumor chiefly in the age of presentation and response to chemotherapy. Radiographically, renal cell carcinoma cannot be distinguished from Wilms tumor. While the natural history of renal cell carcinoma appears to be similar in children and adults, it may have a more favorable prognosis below the age of ten years.     

Treatment strategy for children with Wilms tumor

Wilms tumor has an excellent prognosis according to the findings of the National Wilms Tumor Study (NWTS). The NWTS has been aiming to reduce the intensity of treatment for low-risk groups. Pathologic assessment or statistical analysis has identified the appropriate staging system suited to this treatment regimen. The Japanese Wilms Tumor Study (JWiTS) has been following the NWTS-5 regimen to increase survival rates and tumor-free survival rates from 1996. This study aims to establish a central review system of pathology and to study the presence of WT1 mutation in tumor samples. In addition, JWiTS focuses on developing an online database that can be shared over the Internet. However, the prognosis in patients with malignant rhabdoid tumor of the kidney (MRTK) is still poor. JWiTS has started to consider a new regimen for MRTK.     

Wilms' tumor management

PURPOSE OF REVIEW: The management of Wilms' tumor continues to evolve with two different approaches being taken by the National Wilms Tumor Study in North America and the International Society of Pediatric Oncology in Europe in regards to preoperative chemotherapy. Limiting the duration, dosage, and number of chemotherapeutic agents and the dosage of radiotherapy are common goals in both trials. RECENT FINDINGS: Contralateral exploration of unilateral tumors will no longer be recommended in future National Wilms Tumor Studies. Percutaneous biopsy for tissue diagnosis is quite accurate, but there are concerning complications with its use. Partial nephrectomy is successful for low risk unilateral Wilms tumor, but its indications remain controversial. The surgical complication rate was similar between the National Wilms Tumor Study and the International Society of Pediatric Oncology, but intraoperative tumor spill was higher in the North American trials. Doxorubicin decreased the risk of recurrence in stage III tumors by 50%, and its current dose is not associated with late congestive heart failure. For selected patients, shorter courses of vincristine/dactinomycin or vincristine alone show equivalent results compared to current regimens. A longer course of chemotherapy (including doxorubicin) for clear cell sarcoma improves recurrence-free survival. Patients with Wilms' tumor, aniridia, major genitourinary malformations, and mental retardation, the WAGR syndrome, have a 50% chance of unexplained end-stage renal disease 20 years after treatment. SUMMARY: Less aggressive means of diagnosis and treatment for Wilms' tumor are continuing to achieve very good cure rates while lowering long term morbidity for low risk patients. High-risk patients with unfavorable histology or the WAGR syndrome benefit from more intensive treatment and long-term follow-up.     

成人肾母细胞瘤的诊断与治疗（附12例报告）

目的探讨成人肾母细胞瘤的诊断和治疗方法。方法回顾性分析12例成人肾母细胞瘤患者的临床资料。结果本组患者年龄16-63岁,表现为肉眼血尿2例,腰腹痛6例,4例为体检发现;术前诊断为肾肿瘤9例,肾盂肿瘤3例。12例均行手术治疗,术后病理均诊断为肾母细胞瘤。按照美国国家肾母细胞瘤研究组（NWTS）分期标准,本组分别为Ⅰ期5例、Ⅱ期3例、Ⅲ期3例、Ⅳ期1例。术后辅以放疗和化疗,平均随访41个月,3年生存率为48%。结论成人肾母细胞瘤是一种比较少见的恶性肿瘤,术前确诊困难,手术治疗并辅以放疗、化疗是其主要的治疗方法。