消化管における非上皮性腫瘍の病理

Statistical Study and Pathology of the Non-epithelial Tumors of the Gastrointestinal Tract

　消化管に発生する非上皮性腫瘍は，比較的稀な疾患である．非上皮性腫瘍の発生頻度は消化管腫瘍の1～5％程度といわれているが¹⁾，本腫瘍に関する統計的報告は少ない．今回，悪性リンパ腫を除いた消化管の非上皮性腫瘍について自験例をのべ，あわせて内外の文献を中心に統計的事項を述べてみることにする．

　Non-epithelial tumors of the gastrointestinal tract are very rare. Its incidence is about 1～5％ of the all neoplasmas of the gastrointestinal tract. Benign non-epithelial tumors in the small intestine are occupied about 60％ of all benign tumors. But there is very low frequency in the stomach, colon and rectum. The incidence of the malignant non-epithelial tumors (sarcoma) is very rare,1～2％ of all malignant tumors in stomach and large intestine. However, in the small intestine, it is showed to be over 40％ in sarcoma. Of all benign non-epithelial tumors, histologically leiomyoma and benign lipoma are very common. Most of sarcoma are malignant lymphoma and leiomyosarcoma, and other tumors are very rare.

　It is very important to differentiate leiomyosarcoma from neurogenic sarcoma. Almost cases which were previously reported as neurogenic tumor, especially neurinoma or neurogenic sarcoma of the gastrointestinal tract, are probably leiomyosarcoma and leiomyoma. In this paper we emphasized the importance of histological differential diagnosis between leiomyosarcoma and neurogenic tumors in the gastrointestinal tract. And we reported a case of solitary neurogenic sarcoma of the small intestine.

　Recentely, lymphoid-plasmacytic disorders associated with appearance of a unique serum and urinary protein, which is Fc-fragment of the counterpart of the heavy chain of Ig-G, are known as heavy chain disease. We have experienced a case of heavy chain disease, which was involved the gastrointestinal tract. We cannot find any reports of heavy chain disease involving the gastrointestinal tract. Histologically heavy chain disease shows variable features (reticulum cell sarcoma like and Hodgkin desease like) but not malignant lymphoma, and remarkable plasma cell infiltration was noted. This feature is very characteristic of this disease. Ig-A heavy chain disease (α-chain disease) arises from small intestine. The characteristical histoligical findings is diffuse plasma cell infiltration and clinically associated with malabsorption.