CA19-9高値を示したランブル鞭毛虫症の1例

Giardiasis Accompanied by an Increased Serum CA19-9, Report of a Case

要旨　患者は49歳，男性．下痢と体重減少を主訴に入院し，糖尿病，肝硬変と診断された．入院時よりCA19-9の高値（301.9U/ml）を認めた．下痢が持続したため，消化管X線・内視鏡検査を施行したところ，十二指腸から上部空腸にかけて粗糙粘膜を認め，十二指腸にはアフタ様病変が散在性に観察された．十二指腸生検組織および胆汁中にランブル鞭毛虫を認めたことから，ランブル鞭毛虫症と診断した．metronidazoleによる駆虫で粘膜所見に改善傾向を認め，CA19-9も120.3U/mlまで低下した．自験例では軽微な十二指腸病変にとどまっていたことから，ランブル鞭毛虫症の内視鏡診断には注意が必要と考えられた．

　A 49-year-old man was admitted to our hospital complaining of diarrhea and weight loss. Laboratory data revealed that he was suffering from alcoholic liver cirrhosis and diabetes mellitus. His serum CA19-9 was elevated to 301.9 U/ml. Upper gastrointestinal radiography and endoscopy revealed diffusely coarse mucosa and scattered aphthous lesions in the duodenum and in the proximal part of the jejunum. Numerous trophozoites of Giardia lamblia were detected in the duodenal biopsy specimens and in the bile juice. Based on these findings, we diagnosed the patient as having giardiasis. A treatment by metronidazole improved his abdominal symptoms, as well as findings in the duodenum. His serum CA19-9 was decreased to 120.3 U/ml. Our case suggest that, under radiography and endoscopy, the duodenal involvement in giardiasis may be obscure. Other procedures such as duodenal biopsy should be considered in cases suspected of having giardiasis.