Yoshiyuki Shiga md, Department of Urology, Tsukuba Central Hospital, 1589-3 Kashiwada-chou, Ushiku-city, Ibaraki 300-1211, Japan. Email: firstname.lastname@example.org
Abstract An α-fetoprotein-producing transitional cell carcinoma of the renal pelvis is extremely rare. To our knowledge, this has not been reported previously. We present the first case of an α-fetoprotein-producing transitional cell carcinoma of the renal pelvis in a 70-year-old female.
α-Fetoprotein (AFP)-producing tumors other than hepatocellular carcinoma (HCC) or embryonal cell carcinoma are extremely rare. Although a few cases of AFP-producing adenocarcinoma of the renal pelvis have been reported, there has been no report of an AFP-producing transitional cell carcinoma (TCC) of the renal pelvis.
A 70-year-old woman, showing intermittent gross hematuria from her indwelling nephrostomy tube in the right kidney, was admitted to Tsukuba University Hospital in January 2000. The patient had experienced total cystectomy and partial resection of the right lower ureter for carcinoma in situ (grade 2, pTis, N0, M0, rt-u 0, stage 0is) at the University Hospital in May 1996. The patient had a left nephrectomy for benign renal disease (no details available) 30 years previously. In addition, she has suffered from chronic viral hepatitis for more than 20 years.
After admission, the patient's serum AFP level was measured to screen for HCC. The serum AFP level was found to be extremely high: 24 000 ng/mL. Abdominal computed tomography (CT) showed a smooth-surfaced solid mass in the renal pelvis (Fig. 1). With a clinical diagnosis of AFP-producing renal pelvic tumor, right nephrectomy with resection of the nephrostomy tract was performed on 28 February 2000. Subsequently, hemodialysis was started.
The pathological diagnosis of the renal pelvic tumor was grade 2 TCC with papillary proliferation (Fig. 2a). The tumor had partially invaded the superficial smooth muscle layer. Immunohistological analysis of the tumor demonstrated that TCC cells were strongly positive for AFP (Fig. 2b).
The serum AFP level decreased according to the expected half-life and returned to normal levels 4 months after nephrectomy. However, serum AFP in-creased again 9 months later and metastasis in a retroperitoneal lymph node was found on CT. The patient was irradiated on the retroperitoneal metastatic node with a dose of 40 Gy. The lymph node metastasis decreased in size by 80% after radiation and the AFP level returned to within the normal range. The AFP level was within normal limits until 7 months after radiotherapy; thereafter, the patient began to suffer from gastrointestinal bleeding. Although there was no apparent evidence of cancer recurrence, the patient died of gastrointestinal bleeding in May 2002.
α-Fetoprotein-producing renal pelvic tumor is extremely rare; only three cases have been reported in the English literature.1–3 The histology of the AFP-producing renal pelvic tumors reported was adenocarcinoma in two cases1,2 and adenocarcinoma accompanied by TCC in one case.3 In the latter case, immunohistological analysis revealed that the adenocarcinoma part, but not that of TCC, was positive for AFP.3 In the present case, histological examination did not reveal any adenocarcinoma, but TCC cells were strongly positive for AFP. To our knowledge, this is the first report of AFP-producing TCC arising from the renal pelvis. Because no effective chemotherapy for this rare tumor has been documented and the patient had risk factors for systemic chemotherapy, such as chronic hepatitis and renal failure, we elected to use radiation therapy to treat the lymph node metastasis. Radiotherapy was effective in the present case and resulted in normalization of AFP levels for 7 months. Finally, AFP is not usually produced in normal adult organs, but is found in some cancers, such as HCC, germ cell tumors and, rarely, in some gastrointestinal cancers. At present, there is no conclusive explanation of the mechanism involved in the production of AFP by those cancers. However, on the subject of gastric cancer, Kataoka et al.4 recently reported that the absence of AT motif-binding factor 1, a transcription factor that binds to an AT-rich region in the AFP regulatory element and downregulates an AFP gene, may contribute to AFP gene expression in AFP-producing gastric cancer. The same mechanism may be involved in AFP-producing TCC in the present case.