消化管の非上皮性腫瘍について―その臨床面よりの考察

Non-epithelial Tumor of the Gastrointestinal Tract: Its clinical study

　腫瘍病理学では，腫瘍を良性，悪性に分け，またその発生母地によって上皮性と非上皮性に分類している．本主題の非上皮性腫瘍は，すなわち，上皮性腫瘍でない腫瘍を一括して呼称する名称ということになる．当然，非上皮性腫瘍の中に，良性と悪性が分類される．上皮性悪性腫瘍が癌であり，非上皮性悪性腫瘍は肉腫である．上皮性良性腫瘍としては，ポリープ，腺腫，乳嘴腫などが含まれるが，胃においてはこれらの存在は疑われており，胃ポリープの本質がいわゆる腫瘍ではないとする考え方が強くなっている現在，胃において上皮性良性の真性腫瘍の存在は少ないことになる．一方，非上皮性良性腫瘍としては，消化管のいずれの部位においても平滑筋腫，脂肪腫，線維腫，神経線維腫，血管腫などの存在が，頻度の多少はあれ認められている．このような腫瘍の発生母地による分類のほかに現在，特に胃において臨床的に一般に用いられている“粘膜下腫瘍”という名称がある．本稿においては，まず胃における非上皮性腫瘍と粘膜下腫瘍の関係について考察を加え，ついで各臓器における非上皮性腫瘍の臨床像を分析したい．

　A clinical study of non-epithelial tumor of gastrointestinal tract was discribed in this paper.

　The difference of non-epithelial tumor and submucosal tumor of the stomach was discussed at first. The submucosal tumor of the stomach is found clinically as the semi-spheroid tumor elevated into the lumen of the stomach and covered with same gastric mucosa. The central crater formation on the surface of its tumor is seen in some cases. The localisation of this kind of tumor is in the submucosal or muscle layer of the gastric wall. Usually this tumor is originated from non-epithelial benign tumor like as in leiomyoma, lipoma, neurinoma, neurofibroma etc. But some kind of benign epithelial tumor (cyst and aberrant pancreatic tissue in the gastric wall), inflammatory tumor (eosinophilic granuloma, and some cases of reactive lymphoreticular hyperplasia) and so malignant non-epithelial tumor show same form clinically and are included in the criteria of submucosal tumor of the stomach. Anyhow, the majority of submucosal tumor of the stomach are formed by non-epithelial benign tumor. The nomenclature of the non-epithelial tumor includes the benign and malignant type in its nature.

　The difference, characteristics of incidence, clinical manifestation, and prognosis, etc. of non-epithelial benign and malignant tumors were discussed in every part of digestive tract.

　Leiomyoma is the most common tumor of non-epithelial benign nature in each organ of digestive tract. However, neurogenic tumor and lipoma are very seldom in the oesophagus and colon. Usually the prognosis of this kind of benign tumor after surgery is favorable.

　The incidence of leiomyosarcoma and malignant lymphoma is very different in each organ. In the oesophagus, duodenum and rectum, the frequency of leiomyosarcoma is higher than that of malignant lymphoma. However, in the stomach, jejunum and ileocaecal region malignant lymphoma is more frequent than leiomyosarcoma.

　The prognosis after resection of leiomyosarcoma of the stomach, jejunum and large intestine is favoruable, but is very unfavourable in the rectum. Also the survival result of malignant lymphoma in the ileocaecal region is rather favorable, but not so significant as in the stomach. In some cases of non-epithelial malignant tumor, particularly in malignant lymphoma, the preoperative diagnosis is successfully made in the stomach by cytology and biopsy examinations. Diagnostics in this kind of non-epithelial tumor will be established by the development of radiology, endoscopy, cytology and biopsy under direct observation using endoscopic instruments for each organ.