頭蓋内germ cell tumorの腫瘍マーカー—体液中および腫瘍組織中のgonadotropinについて

GONADOTROPIN, AS A TUMOR MARKER, IN BODY FLUID AND TUMOR TISSUES OF GERM CELL TUMORS

　抄録　頭蓋内germ cell tumor （GCT）例の腫瘍マーカーとして，human chorionic gonadotropin （HCG）を選択し，体液中のどの値が腫瘍マーカーとして最も信頼性が高く有用であるかについて検討した。対象として，germinoma 9例，embryonal carcinoma 1例，yolk sac tumor 1例，choriocarcinoma 2例（原発性1，転移性1），teratoma 3例を選んだ。各症例の血清，髄液，尿中におけるHCG （α，β）またはHCG（β）を測定し，化学療法や放射線療法にともなう変動を検索する一方，手術または剖検で腫瘍組織が得られた症例には，免疫組織化学的手法で腫瘍組織中におけるHCG （β）の局在を検討した。原発性GCT例においては髄液中のHCGが最も高値を示し，転移性の例では血清中の値が最も高かった。また，体液中HCGが30IU／l以上の例では，その腫瘍組織中にHCG （β）の局在が証明され，腫瘍からの分泌によるものであり，10IU／l未満の例は間脳下垂体系の障害にともなう間接的なものであった。間接的な原因によるHCGの上昇はlutein hormoneと交叉したα-subunitであった。したがって，腫瘍マーカーとしてはHCG （β）の測定が最も有効であり，転移性のものか原発性のものかを判定するには，血清中の濃度と髄液中の濃度を比較すればよい。

The value of gonadotropin in the body fluids of germ cell tumor patients is its usefulness as a tumor marker. It is also used for differential di-agnosis and/or judgement of therapeutic effects. In order to clarify the most effective value of gonadotropin as a tumor marker in the body fluids, we compared the value in serum, liquor and urine with one another.

The liquor contained highest (1650 IU//) value of gonadotropin in the primary intracranial germ cell tumors, mostly in choriocarcinoma. But the gonadotropin value was highest (3050 IU//) in the serum of secondary intracranial choriocarcinoma. Chiasmal germ cell tumor, except choriocarcinoma, which does frequently secrete gonadotropin (a, ,^) showed moderate or very high values in the liquor. However, pineal germ cell tumors rarely secrete gonadotropin and sometimes mild high value are obtained in the serum without gonadotropin secre-tion immunohistochemically. In such cases, the gonadotropin may be increased by indirect mecha-nism of gonadotropin-secretion following pineal disorder. In most of such cases, the gonadotropin was not human chorionic gonadotropin (HCG) but lutein hormone (LH). Because a-subunit of such gonadotropin has the same structure, their anti-bodies show immunologic cross reaction. So, a count of /3-subunit gonadotropin in the serum or liquor is the best way for differential diagnosis or judgement of therapeutic effects.

From our results, it is considered that the tumor secretes HCG if the serum p-HCG value was higher than 30 IU//, and that it doesn't secrete HCG if (3-HCG value was lower than 10 IU// or non cal-culatable. The mild increased HCG may be caused by hypothalamo-diencephalic disorder such as pi-neal tumor.

The HCG value was highest in liquor of primary intracranial germ cell tumors, but highest in serum of metastatic choriocarcinoma patient.