'Prechronous' metastasis in clear cell renal cell carcinoma: a case report.

INTRODUCTION: Although metastatic carcinoma in the presence of an occult primary tumor is well recognized, underlying reasons for the failure of the primary tumor to manifest are uncertain. Explanations for this phenomenon have ranged from spontaneous regression of the primary tumor to early metastasis of the primary tumor before manifestation of a less aggressive primary tumor. We report a case of 'prechronous' metastasis arising from clear cell renal cell carcinoma, where metastatic disease initially manifested in the absence of a primary renal tumor, followed by aggressive growth of the primary renal lesion. CASE PRESENTATION: A 43-year-old Malay man initially presented to our facility with fever and cough. He subsequently underwent surgical resection of a 9 cm right-sided lung mass found on radiological examination. Histology showed a high-grade clear cell tumor with sarcomatoid differentiation, suggestive of a metastasis from clear cell renal cell carcinoma. However, no concurrent renal lesions were noted on computed tomographic evaluation at that time. Then, four months after lung resection, he presented with a subcutaneous mass in the left loin, as well as right loin discomfort. Computed tomography scanning revealed a 10 cm right renal mass, with renal vein and inferior vena cava invasion, as well as recurrent disease in the right thorax. Histological examination of the excised subcutaneous mass revealed a high-grade carcinoma consistent with clear cell renal cell carcinoma. CONCLUSIONS: This is the first reported case of prechronous metastasis of renal cell carcinoma, with metastatic disease manifesting prior to the development of the primary lesion. The underlying mechanism is uncertain, but our patient's case provides anecdotal support for the early dissemination model of metastasis.

Papillary renal cell carcinoma with metastatic laparoscopic port site and vaginal involvement: a case report.

INTRODUCTION: Laparoscopic port-site metastasis is a rare but well recognized outcome following surgery in urological cancers, with its etiology not clearly understood. Additionally, vaginal metastasis in clear cell renal cell carcinoma is rare, and has not been previously reported in the setting of papillary renal cell carcinoma. CASE PRESENTATION: We present the case of a 71-year-old Chinese woman with metastatic type II papillary renal cell carcinoma with histologically verified vaginal involvement and a concurrent laparoscopic port-site metastasis. This was also associated with a unique constellation of widely disseminated metastatic sites, which include a local relapse, the peritoneum and the urethra. CONCLUSION: Laparoscopic port-site metastases are associated with the presence of advanced cancer with multiple sites of metastasis. We hypothesize from the findings of our report and background data that this phenomenon is more likely to be related to tumor factors rather than operative factors. We also present what is, to the best of our knowledge, the first reported case in the literature of vaginal and urethral metastasis and the second reported case of laparoscopic port-site recurrence.