Bladder metastasis with additional metastases in multiple other organs 4 years after radical nephrectomy for clear cell renal cell carcinoma: a case report and review of the literature.

BACKGROUND: Renal cell carcinoma rarely metastasizes to the bladder, and its biological behavior is not yet fully understood. CASE PRESENTATION: In our case (54-year-old Japanese woman), computed tomography evaluation suggested the presence of a bladder metastasis, associated with additional metastases in the lungs, mediastinal lymph nodes, ribs, and renal bed, 4 years after radical nephrectomy for renal cell carcinoma. The histological findings of the metastatic bladder tumor were consistent with those of clear cell carcinoma. The mediastinal lymph node, rib, and renal bed metastases responded to treatment with an immune checkpoint inhibitor administered for 12 months after surgery for the bladder and lung metastases. In patients with bladder metastasis, absence of metastases in other organs and an interval of more than 1 year after nephrectomy are known to be favorable prognostic factors. Interestingly, in our case, the bladder metastasis was detected more than 1 year after nephrectomy, which was a favorable factor, but there were also metastases in other organs, which was an unfavorable factor. Therefore, we reviewed the literature, including that pertaining to targeted therapy and immune checkpoint inhibitor therapy published in the last two decades, to analyze the clinical significance of the presence of additional metastasis in other organs in renal cell carcinoma (clear cell type, which is the predominant subtype) patients with bladder metastasis. CONCLUSIONS: Patients with bladder metastasis after nephrectomy for renal cell carcinoma also having metastases in other organs may respond to targeted therapy and immune checkpoint inhibitor therapy. This may suggest that the interval to relapse in the bladder after nephrectomy may be a more important prognostic factor than the presence of synchronous metastases in other organs.

[A case of papillary cystadenoma of the epididymis mimicking a testicular tumor].

A 68-year-old male presented with painless left scrotal enlargement of one year duration. Ultrasound, computed tomography (CT) and magnetic resonance imaging showed a multilocular cystic mass, 10×7.5× 8.5 cm in size, in the left scrotum. The intracystic fluid was partially hemorrhagic. A solid part of the tumor, seen at the base of the scrotum, was partially calcified and was enhanced by contrast medium. The left testis could not be identified by imaging studies. Although CT imaging showed a simple cyst in the right kidney, no other lesions in the kidneys, adrenal glands, pancreas or the central nervous system were detected. Serum tumor marker values for testicular cancer were within the normal range. Under the pre-operative diagnosis of a left testicular tumor, left high orchiectomy was performed. Grossly the specimen consisted of a multilocular cystic tumor, 12.5×8.5×8.5 cm in size, with a 2.7 cm tan-colored solid component within the wall of the cyst. The left testis was atrophic, 1.3 cm in size, and demonstated no continuity with the solid part of the tumor. Histologically, the solid component of the tumor showed tubular and papillary growth of cuboidal and columnar tumor cells with clear cytoplasm. Histopathological diagnosis of papillary cystadenoma of the epididymis (PCE) was made. Von Hippel-Lidau disease was ruled out by subsequent genetic analysis. After follow up for 18 months, there was no sign of recurrence. To our knowledge, this is the 33rd and the largest case of PCE reported in Japan.