Koyama Masamichi, Terauchi Takashi, Koizumi Mitsuru, Tanaka Hiroko, Takeuchi Kengo
Department of Nuclear Medicine Diagnostic Imaging Division of Pathology, The Cancer Institute Hospital of JFCR, Tokyo, Japan.
Medicine (Baltimore). 2016 Aug;95(34):e4646. doi: 10.1097/MD.0000000000004646.
F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is useful for the staging and assessment of treatment response in patients with lymphoma. Occasionally, benign lesions demonstrate avid FDG uptake and result in false positive findings.
We report the case of an 82-year-old man presenting with cutaneous lesions, which were histopathologically diagnosed as intravascular lymphoma. FDG-PET/CT for staging demonstrated an FDG-avid mass extending from the right maxillary sinus to the nasal cavity, moderate uptake in the adrenal glands, mild uptake in the knee and the foot, and faint uptake in the skin and subcutaneous tissue of the legs. He subsequently underwent biopsy of the paranasal mass, which was diagnosed as oncocytic Schneiderian papilloma without lymphoma invasion. Glucose transporter (GLUT) 1 staining was highly positive in the papilloma cells, resulting in high FDG avidity. After completion of chemotherapy, the abnormal FDG uptakes in the skin, soft tissue, and adrenal glands disappeared on PET/CT. However, avid FDG uptake persisted in the sinonasal Schneiderian papilloma for 15 months before regression.
Benign tumors with oncocytic components may show avid FDG uptake. Therefore, correct diagnosis of oncocytic Schneiderian papilloma on FDG images is difficult when other accompanying malignant tumors, especially lymphoma, are present. If post-therapeutic PET/CT images show a discordant lesion, oncocytic tumors, albeit uncommon, should be considered in the differential diagnoses.
F-18氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描（FDG-PET/CT）对淋巴瘤患者的分期及治疗反应评估很有用。偶尔，良性病变会表现出FDG摄取增加，导致假阳性结果。
我们报告一例82岁男性，其出现皮肤病变，经组织病理学诊断为血管内淋巴瘤。用于分期的FDG-PET/CT显示一个从右上颌窦延伸至鼻腔的FDG摄取增加的肿块，肾上腺有中度摄取，膝盖和足部有轻度摄取，腿部皮肤和皮下组织有微弱摄取。随后他接受了鼻旁肿块活检，诊断为嗜酸细胞性施耐德乳头状瘤，无淋巴瘤侵犯。葡萄糖转运蛋白（GLUT）1染色在乳头状瘤细胞中呈高度阳性，导致FDG摄取增加。化疗完成后，皮肤、软组织和肾上腺的异常FDG摄取在PET/CT上消失。然而，鼻窦嗜酸细胞性施耐德乳头状瘤的FDG摄取增加持续了15个月才消退。
含有嗜酸细胞成分的良性肿瘤可能表现出FDG摄取增加。因此，当存在其他伴随的恶性肿瘤，尤其是淋巴瘤时，在FDG图像上准确诊断嗜酸细胞性施耐德乳头状瘤很困难。如果治疗后的PET/CT图像显示有不一致的病变，鉴别诊断时应考虑嗜酸细胞瘤，尽管其并不常见。
