Prosch H, Mirzaei S, Oschatz E, Strasser G, Huber M, Mostbeck G
Otto Wagner Hospital, Department of Radiology, Sanatoriumsstrasse 2, 1140 Vienna, Austria.
Br J Radiol. 2005 Aug;78(932):758-61. doi: 10.1259/bjr/55106848.
Positron-emission-tomography (PET) with fludeoxyglucose F-18 ([(18)F] fluoro-2-deoxy-D-glucose, FDG) has become an established imaging modality in patients with lung cancer for mediastinal lymph node staging and the detection of extrathoracic metastases. However, tracer accumulations are not limited to malignant tissue but are also found in muscles and benign inflammatory processes. We report on two patients with lung cancer in whom FDG-PET revealed suspicious tracer accumulations in the buttock. Ultrasound (US) revealed a hyperechogenic nodule with poorly defined margins in both patients. On specific inquiry both patients reported on repeated "intramuscular" gluteal injections. Histology after US guided biopsy showed an accumulation of macrophages within fibrous tissue, compatible with injection site granulomas. The reported cases underline that (18)F-FDG may accumulate in benign, ancillary processes that have to be distinguished from distant metastases. Tracer accumulation in the buttocks may be highly suggestive of injection site granulomas, especially if the patient reports on "intramuscular" injections. In this setting, US is a widely available modality to distinguish metastasis from adipose tissue necrosis.
使用氟代脱氧葡萄糖F-18（[18F]氟-2-脱氧-D-葡萄糖，FDG）的正电子发射断层扫描（PET）已成为肺癌患者纵隔淋巴结分期和胸外转移检测的一种既定成像方式。然而，示踪剂的积聚不仅限于恶性组织，在肌肉和良性炎症过程中也可发现。我们报告了两名肺癌患者，其FDG-PET显示臀部有可疑的示踪剂积聚。超声（US）显示两名患者均有边界不清的高回声结节。经详细询问，两名患者均报告有反复的“肌肉内”臀肌注射史。超声引导下活检后的组织学检查显示纤维组织内有巨噬细胞积聚，符合注射部位肉芽肿表现。报告的病例强调，18F-FDG可能积聚在良性辅助性病变中，这些病变必须与远处转移相鉴别。臀部的示踪剂积聚可能高度提示注射部位肉芽肿，特别是当患者报告有“肌肉内”注射史时。在此情况下，超声是一种广泛可用的区分转移灶与脂肪组织坏死的检查方法。
