摘要
BACKGROUND Thymic carcinoma is a rare,aggressive tumor arising from the thymus.In less than 7%of patients with thymic carcinoma,extrathoracic metastases occur in the extrathoracic lymph nodes,liver,and bone.Isolated splenic metastasis can occur but is very uncommon.To date,only 2 cases of splenic metastases from thymic carcinoma have been reported.CASE SUMMARY A 45-year-old man presented with chronic cough,dyspnea,persistent hoarseness and unintentional weight loss 17 kgs in 6 mo.Neck magnetic resonance imaging revealed a large,lobulated,soft-tissue mass measuring 5.4 cm×6.6 cm×3.8 cm which involved the left superior mediastinum and supraclavicular fossa.Chest computed tomography(CT)revealed a confluent and lobulated soft tissue mass encased the right brachiocephalic artery,right and left carotid arteries,and left subclavian artery in the mediastinum.A fluorodeoxyglucose-positron emission tomography was arranged for malignancy survey.The image revealed intense fluorodeoxyglucose avidity in a soft tissue lobulated mass occupying the superior mediastinum,over the cystic lesion in the spleen and in few enlarged nodules over the left supraclavicular fossa.CT-guided biopsy of the thymic mass and the ultrasound-guided biopsy of the splenic lesion were consistent with a thymic carcinoma with splenic metastasis.The patient was diagnosed of thymic carcinoma,cT2N2M1b,stage IVb.CONCLUSION A fluorodeoxyglucose(FDG)-positron emission tomography(PET)scan can provide a useful diagnostic value in conjunction with pathological result in evaluating tumor staging.Our case emphasizes the utility of FDG-PET for metastasis detection in thymic carcinoma.