Rare Thyroid Cartilage and Diaphragm Metastases from Lung Cancer Visualized on F-18 FDG-PET/CT Imaging

Abstract

Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) has evolved as a useful imaging modality in the assessment of a variety of cancers, especially for tumor staging and post treatment monitoring. It provides metabolic information. Although, when used alone, relative lack of anatomic landmarks, is a major limitation of PET imaging, this limitation of PET imaging is overcome by the availability of integrated PET/CT imaging. PET and CT images are acquired in one procedure, yielding fused anatomical and functional data sets. Studies with integrated PET/CT imaging have shown promising results. In this case, we present an interesting integrated PET/CT imaging in a lung cancer patient with rare, diaphragm and thyroid cartilage metastases.

Conflict of interest: None declared.

Keywords: PET/CT; Lung cancer; Diaphragm metastasis; Thyroid cartilage metastasis.

Figure 1. MIP image of PET/CT (a) demonstrated a right upper lobemass (SUVmax: 28.0), left lower lobe lung nodule (SUV_max: 3.6),paracardiac lymph node (SUV_max: 6.2), bilateral adrenal lesions(SUVmax: 18.3-right and 4.7-left), intraabdominal lymph nodes(SUV_max: 5.6), a 12 mm lesion on anterior thyroid cartilage withdestruction on CT imaging (SUV_max: 6.5) (a,b,c,d) and multiple bonelesions with increased FDG uptake were detected. Additionally,PET/CT showed areas of increased tracer uptake between rightlower mediastinum and liver. The ill-defined lesions adjacent to theliver were missed on CT. The exact localization of these lesions couldonly be determined on PET/CT imaging that could be diagnosed asmetastases to the diaphragm (a,e,f,g)