胃小細胞癌の1例

Small Cell Carcinoma of the Stomach, Report of a Case

要旨　患者は64歳，男性．食思不振と心窩部痛を訴えて来院した．胃X線・内視鏡検査で，胃前庭部前壁に2型様の腫瘤を認め，周堤内に大小2個の陥凹を有し，また，周堤から伸びる数本のbridgng foldに類似したひだを認めた．生検組織診断は小細胞癌で，一部に中分化型腺癌を併存していた．小細胞癌の腫瘍細胞は，Grimelius染色陽性で，免疫組織化学的にはNSE陽性，CEA，UCHL-1，L26陰性であった．血清NSE値は増加していた．腹部CT，超音波内視鏡で著明な腹腔内リンパ節腫大があり，進行期と診断，化学療法（carboplatin＋etoposide）を施行した．一時期，腫瘍の縮小効果を認めたが，7か月後に死亡した．胃小細胞癌の報告は少なく，文献的に考察を加えた．

　A 64-year-old male was admitted to our hospital because of loss of appetite and epigastric pain. In the umbilical region there was a firm ill-defined mass which was slightly tender on pressure. No enlarged superficial lymph nodes were detected. X-ray examination of the upper gastrointestinal tract and gastroendoscopic examination revealed a large tumor at the anterior wall of the gastric antrum. The tumor seemed to be a type 2 lesion. It was somewhat similar to a submucosal tumor because it had a bridging fold-like appearance. Biopsy specimens obtained from the tumor were consistent with a diagnosis of small cell carcinoma, although, histologically, they showed partly moderately differentiated adenocarcinoma. Tumor cells of small cell carcinoma were stained positive by Grimelius stain, and were also stained positive for neuron-specific enolase (NSE), negative for CEA, UCHL-1 and L 26 using the immunohistochemical method. Significantly elevated serum NSE levels accompanied the tumor.

　Although four courses of chemotherapy (carboplatin+etoposide) were carried out, the patient died seven months after admission.

　We described the clinicopathological features of our case and reviewed the literature in Japan.