Kato Takashi, Ikari Shuji, Hirata Kenji, Machida Takuro, Nakamura Hideaki, Meguro Takashi, Morita Takayuki, Takahashi Toshiyuki, Tamaki Nagara, Horita Shoichi
Department of Internal Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Case Rep Gastroenterol. 2012 May;6(2):415-24. doi: 10.1159/000339916. Epub 2012 Jun 26.
Intraductal oncocytic papillary neoplasm (IOPN) of the pancreas is a rare pancreatic tumor. To date, there have been three case reports of IOPN which showed strong positivity on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), raising the possibility of distinguishing IOPNs from other intraductal papillary mucinous neoplasms (IPMNs) using FDG-PET. However, all three cases had large tumors, approximately 10 cm in diameter, and there are no case reports of FDG-PET findings of small IOPNs, i.e. tumors the average size of malignant IPMNs (3-5 cm). We report two cases with IOPN of average size with FDG-PET findings. Computed tomography (CT) showed a multilocular cystic lesion 4 cm in diameter with a mural nodule 1 cm in diameter (case 1) and a cystic lesion 5 cm in diameter with a papillary mural nodule 4 cm in diameter (case 2). FDG-PET showed abnormal uptake at the same location as the pancreatic tumor revealed by CT in both cases. The maximum standardized uptake values of the lesions were 3.4 and 4.2, respectively. Surgical resection was performed and the tumor was diagnosed as IOPN with carcinoma in situ (case 1) and IOPN with minimal invasion (case 2). FDG-PET may be useful for diagnosing malignancy in IOPN, as it is in IPMN. However, in our two cases, strong accumulation was not observed in the IOPNs, which were within the average size range of malignant IPMNs.
胰腺导管内嗜酸性乳头状肿瘤（IOPN）是一种罕见的胰腺肿瘤。迄今为止，已有3例IOPN的病例报告显示其在18F-氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）上呈强阳性，这增加了使用FDG-PET将IOPN与其他导管内乳头状黏液性肿瘤（IPMN）区分开来的可能性。然而，所有这3例病例的肿瘤都很大，直径约为10厘米，目前尚无关于小IOPN（即平均大小为恶性IPMN的肿瘤，3-5厘米）的FDG-PET检查结果的病例报告。我们报告2例平均大小的IOPN的FDG-PET检查结果。计算机断层扫描（CT）显示，1例为直径4厘米的多房囊性病变，伴有1厘米直径的壁结节（病例1），另1例为直径5厘米的囊性病变，伴有4厘米直径的乳头状壁结节（病例2）。FDG-PET显示，这2例病例中FDG摄取异常的部位与CT显示的胰腺肿瘤部位相同。病变的最大标准化摄取值分别为3.4和4.2。2例均接受了手术切除，肿瘤被诊断为原位癌的IOPN（病例1）和微浸润的IOPN（病例2）。与IPMN一样，FDG-PET可能有助于诊断IOPN的恶性程度。然而，在我们的2例病例中，平均大小在恶性IPMN范围内的IOPN未观察到强烈的FDG聚集。
