消化管

Diagnostic imaging of gastrointestinal malignant lymphoma

消化管悪性リンパ腫は消化管悪性腫瘍の約1～2％と頻度は低いものの，悪性リンパ腫でみれば消化管はすべての節外リンパ腫の約40％を占めており，実臨床では比較的遭遇することも多い。臓器別では胃が最も多く（50～60％），次いで小腸（20～30％），大腸（5～15％）の順で，食道のものはまれ（＜1％）である^1）。これは食道が他の消化管と比較して，リンパ網内系組織が少ないためとされる。

Gastrointestinal malignant lymphomas are infrequent, accounting for approximately 1-2％ of all gastrointestinal malignancies. However, it accounts for about 40％ of all extranodal lymphomas and is relatively frequently encountered in practice. By organ, the stomach is most frequently involved, followed by the small intestine and large intestine, with esophageal cases being rare.

The imaging findings of gastrointestinal malignant lymphoma are diverse, and except in typical cases, the diagnosis is often difficult. The diagnosis also requires extensive knowledge of imaging studies such as endoscopy, gastrointestinal angiography, CT, FDG PET/CT, and MRI. In this article, we describe the main cases of gastrointestinal malignant lymphoma that we have experienced and discuss the key points of diagnostic imaging.