原発性小腸癌の画像診断—CTを中心に

Computed Tomography Findings of Primary Small Intestine Cancer

要旨●原発性小腸癌は消化管悪性腫瘍の0.1〜1.0%とまれな腫瘍であり，CT所見についてもまとまった報告は多くない．限られた報告ではあるが，小腸癌のCT所見では偏心性病変や内腔狭窄，潰瘍形成などが報告されている．本邦における過去5年間の症例報告では狭窄を示す病変が大半であったが，当院で経験した7例の検討では，狭窄性の病変の他，悪性リンパ腫に類似するような内腔の拡張を示す病変がみられた．病理組織学的所見との対比では腫瘍間質の線維化と狭窄，壊死や髄様増殖と拡張との間に関連が疑われた．小腸腫瘍のCT診断においては原発巣の形態のみならず，リンパ節転移や遠隔転移の有無，転移巣や原発巣の壊死や不均一さといった性状を合わせた検討が必要と考える．

　Tumors of primary small intestine cancer are considerably rare, which include 0.1%-1.0% of malignant tumors of the gastrointestinal tract. Furthermore, few reports exist on the CT（computed tomography）findings. However, these studies have reported CT findings of small intestine cancer showing eccentric lesions, luminal stenosis, and ulcer formation. In the case reports published in the past 5 years in Japan, the majority of the lesions showed stenosis. However, in the 7 cases experienced at our hospital, in addition to stenotic lesions, dilation of the lumen similar to malignant lymphoma was observed. In contrast to pathological findings, a link was suspected between tumor interstitial fibrosis and stenosis, necrosis, and medullary proliferation and dilation.

　In CT diagnosis of small intestine tumor, it is necessary to examine not only the primary lesion but also lymph node metastasis and distant metastasis, necrosis, or heterogeneity of the metastatic lesion and primary lesion.