消化管follicular lymphomaの特徴：臨床的立場から―X線を中心に

Radiological Feature of Follicular Lymphoma in the Gastrointestinal Tract

要旨　当科で経験した消化管原発follicular lymphoma（FL）5例と全身性FL 12例の臨床的特徴とX線造影検査を中心とした画像的特徴について述べた．消化管原発FLのX線造影検査所見は5例中4例が細顆粒状の隆起を，1例がMLP様隆起を示した．全身性FL12例中4例は細顆粒状の隆起，2例がMLP様の隆起を示し，画像所見は消化管原発FLと同様の所見であった．全身性FLはこれらの所見のほかに，SMT様の隆起性病変を呈するものが4例，肉眼的には明らかな異常所見を認めない症例も2例存在した．以上から，消化管原発FLのX線所見は，細顆粒状の隆起性病変が主体であり，さらに，全身性FLではSMT様隆起などの多彩な変化が混在する特徴があると考えられた．また，これらの所見の大半は小腸に限局しており，本疾患の診療にあたっては，X線造影検査などで小腸を含めた全消化管の検索は必須であると考えられた．

　Radiological features of gastrointestinal (GI) lesions in patients with follicular lymphoma (FL) were reviewed. From 1995 to 2007, 17 patients with GI FL, who were diagnosed on the basis of histological findings, strong immunoreactivity for B-cell markers and positive for rearrangements of IgH and/or Bcl-2 gene, underwent radiological examination in our hospital. These patients were classified into 2 categories, primary GI FL (5 cases) and systemic FL (12 cases), according to Dawson's classification. Four radiological features of GI FL were revealed as follows:multiple small elevated plaques in 4 cases with primary GI FL and 4 cases with systemic FL, multiple lymphomatous polyposis in 1 case with primary GI FL and 2 cases with systemic FL, mimicking submucosal tumor (SMT) in 4 cases with systemic FL, and no abnormal findings in 2 cases with systemic FL. Almost all of these findings were confined to the small intestine, suggesting the advantage of radiological examination which can provide information of the entire intestine. Thus“multiple small elevated plaques”and“multiple lymphomatous polyposis”were regarded as major features of primary GI FL whereas systemic FL revealed various findings on radiological examination.“Multiple small elevated plaques”appears to be a specific finding to distinguish FL from diffuse large B cell lymphoma in the GI tract. Future analysis with a large number of lymphoma patients is needed to clarify the radiological features of GI FL.