転移巣よりみつかった最大径3cm以下の腎細胞癌の2例

Renal Cell Carcinoma Measuring below 3cm with Distant Metastasis:Report of Two Cases

　骨転移巣よりみつかった腫瘍最大径3cmと2.5cmの腎細胞癌を1例ずつ経験した。両者はそれぞれ腎摘除術後1年，4年で癌死した。1970〜1995年の間に，当センターでは長径3cm以下の腎癌を15例経験した（全体の10％）。そのうち静脈浸潤を4例に認め，今回の2例も顕微鏡的に静脈浸潤を認めた。このことより，3cm以下の腎細胞癌でも静脈浸潤が存在する場合は遠隔転移を来す可能性があることが示唆された。

We experienced two cases of renal cell carcinoma measur-ing 3cm and 2.5 cm in diameter with bone metastasis. Pain caused by bone disease was a chief complaint in both cases. They died of cancer 1 year and 4 years after nephrectomy. Tumor growth into vein was seen in 4 cases out of 15 patients with renal cell carcinoma below 3cm in diameter whose prognosis was considered as very good, between 1970 and 1995 in our institute. Two metastatic cases had microscopic tumor thrombi. These Findings suggest venous invasion in renal cell carcinoma, even though tumor diam-eter is below 3cm, is highly associated with metastatic spread.