thymic carcinoma is a rare type of cancer , which differs from thymoma regarding its aggressive clinical behavior . the majority of patients with thymic carcinoma present at an advanced stage and have a poor prognosis ( 1,2 ) . however , a proportion of the patients who achieve long - term survival develop disease relapse and are candidates for salvage therapy , such as re - resection , radiotherapy , or other modalities ( 35 ) . we herein present the 20-year clinical course of a patient initially diagnosed with stage ivb thymic carcinoma that developed bidirectional metastases toward the pleural and lymph nodes , which were successfully treated with repeated chemotherapy , surgery and radiotherapy , followed by low - dose steroid therapy . a 50-year - old man visited a regional hospital 20 years prior with hemoptysis and a febrile state . a chest x - ray revealed a 65-cm solid mass in the hilum of the left lung , directly invading the mediastinum , with left phrenic nerve palsy ( fig . squamous cell carcinoma was diagnosed by percutaneous needle biopsy . based on the clinical diagnosis of t4n0m0 lung cancer , sequential chemoradiotherapy with two cycles of mytomycin c , vindecine and cisplatin ( mvc regimen ) , and radiotherapy of 60 gy was administered . the patient was subsequently referred to the osaka medical center for surgery and he underwent en bloc resection of the left upper lobe , mediastinal lymph nodes , left brachiocephalic vein , pericardium and thymus via a left hemiclamshell approach . the left brachiocephalic vein was reconstructed using a gore - tex graft ( gore medical , flagstaff , az , usa ) . as it was included in the radiation field , the final pathological diagnosis was thymic carcinoma with mediastinal lymph node metastasis ( masaoka stage ivb ) . eleven years after the initial operation , the patient underwent high anterior resection for colon cancer at another hospital . twelve years and six months after the initial operation , a heterogeneous mass with a maximal diameter of 10 cm in close contact with the 12th thoracic to the 2nd lumbar vertebrae was identified on follow - up computed tomography ( ct ) . as no definitive diagnosis was made by needle biopsy , oral tegafur - uracil / leucovorin was administered and a partial response was obtained . sixteen years after the initial operation , at 66 years of age , the patient was referred to the yao municipal hospital ( yao , japan ) for investigation of an acute - onset left back pain . a ct scan revealed a re - growing left paravertebral mass that extended into the 1st intervertebral foramen ( fig . 2 ) . magnetic resonance imaging demonstrated that the mass exhibited a low signal intensity on t1-weighted images and a high signal intensity on t2-weighted and diffusion - weighted images . at that time , pleural recurrence of the thymic carcinoma at the costodiaphragmatic recess or a neurogenic tumor was suspected , and surgery was performed for the purpose of a definitive diagnosis and treatment . intraoperatively , a mass sized 8.54.07.0 cm was identified at the bottom of the left chest cavity , in close contact with the 12th thoracic and 1st lumbar vertebrae , and the 11th and 12th ribs . although the mass was resected with the surrounding connective tissue , including the ribs , the resection was incomplete due to the invasive nature of the mass at the intervertebral foramen . pathologically , the mass was composed of highly atypical epithelioid cells with nuclear atypia and eosinophilic cytoplasm in a fibrotic stroma . the ki-67 index was 27% , with positive reactivity for cd5 and cytokeratin ae1/ae3 , and negative reactivity for c - kit , synaptophysin , chromogranin and thyroid transcription factor 1 . after the operation , 46 gy/23 fr of adjuvant radiation therapy was delivered to the resection margin site , including the intervertebral foramen . twenty months following metastasectomy , positron emission tomography / ct revealed a left subclavicular lymph node metastasis and three new pleural metastases ( fig . the patient received systemic chemotherapy comprising three cycles of carboplatin ( area under the curve 5 on day 1 , every 21 days ) and paclitaxel ( 200 mg / m on day 1 , every 21 days ) . therefore , radiation therapy was delivered ( 46 gy/23 fr ) to all four lesions . the chest ct showed that the left subclavicular lymph node metastasis had markedly shrunk , but the pleural metastases showed no marked changes . therefore , complete excision of the three pleural masses was conducted with clearance of all the intervening connective tissue , combined with partial resections of the diaphragm and lung , 18 years after the initial operation . oral administration of prednisolone ( 30 mg / day ) was initiated to control the pneumonia . two months after surgery , the dose was tapered by 5 mg / day every 2 weeks . the eosinophilic pneumonia , as well as the patient 's general condition , including wound pain , markedly improved , and he requested continuous daily oral administration of 5 mg prednisolone . the patient is currently disease - free and has received low - dose prednisolone for 20 months . thymic epithelial neoplasms are a relatively rare type of cancer , with an annual incidence of 0.15/100,000 person - years ( 6 ) . a previous report indicated that the incidence of nodal metastases in patients with thymic carcinoma was 26.8% ( 1 ) . it has been confirmed by several studies that patients with thymic carcinoma receiving complete resection ( r0 ) exhibit a more favorable long - term survival compared with those who undergo incomplete resection or do not receive surgery ( 1,5 ) . wright et al reported that the recurrence rate of type c thymoma ( thymic carcinoma ) is 50% ( 8) . most thymic carcinomas present at an advanced stage and have a high frequency of relapse , even after complete resection , which indicates the need for a multidisciplinary therapeutic approach ( 5 ) . surgery may be a reasonable option in patients with localized recurrence that can be completely resected ( 3,4 ) . chemotherapy is based on low - level evidence : platinum - based doublet chemotherapy has achieved some beneficial effects ( 10 ) . according to a japanese nationwide database study , stage ivb thymic carcinoma patients showed a relatively favorable survival if they underwent r0 resection for locoregional nodal and pulmonary metastases , with 37% 10-year recurrence - free survival and 39% 10-year overall survival ( 5 ) . we were able to perform r0 resection for the primary site in our patient , with combined resection of the left upper lobe of the lung , left brachiocephalic vein and pericardium after chemoradiotherapy . repeated metastases at the bottom of the left chest cavity and left subclavicular lymph nodes were controlled with chemotherapy , surgery and radiotherapy . over the last 20 months , we have continued to administer low - dose oral prednisolone ( 5 mg / day ) , without recurrence . glucocorticoids are often administered to patients with thymomas to treat associated symptoms of myasthenia gravis , rather than the tumor itself . funakoshi et al reported that thymoma and thymic carcinoma express glucocorticoid receptors , and glucocorticoids may directly affect tumor cells in addition to affecting associated lymphocytes ( 11 ) . there have been a few reports describing the marked clinical response of refractory thymoma , but not of thymic carcinoma ( 12 ) . although the glucocorticoid receptor expression of tumor cells was not investigated in our patient , low - dose prednisolone , which was administered to treat eosinophilic pneumonia , may promote the response of resistant cells to multidisciplinary treatment and maintain a disease - free status in our patient . in conclusion , the multidisciplinary treatment described herein may achieve long - term survival in patients with stage ivb thymic carcinoma .
thymic carcinoma is a rare type of cancer that is more aggressive and is associated with a poorer prognosis compared with thymoma . 
 no definitive clinical management of this disease has been established to date . 
 this report describes the 20-year clinical course of a 50-year - old male patient who was successfully treated for initially diagnosed stage ivb thymic carcinoma . 
 thymo - thymectomy combined with resection of the surrounding organs was performed on december 1995 with curative intent ( r0 ) after neoadjuvant chemoradiotherapy . from june 2008 until present , four pleural and subclavicular lymph node metastases have been treated with chemotherapy , radiotherapy and surgery , followed by low - dose oral steroid therapy . the patient has remained disease - free for the last 20 months since the initiation of prednisolone treatment . thus , multidisciplinary treatment may achieve long - term survival in patients with stage ivb thymic carcinoma .