Unusual Methastatic Spread from Resected Masaoka IVa Thymoma

Introduction: Thymoma is a rare tumour arising from anterior mediastinum. Surgery for early stages and multimodal management for the advanced ones can provide a durable remission of disease. Even many years after the first presentation, Thymomas can show metastatic spread. CASE Ten years ago a 55-years old woman came to our observation for a large mediastinal mass associated with multiple pleural lesions. Diagnosis of Thymoma was achieved by a transthoracic biopsy. After induction chemotherapy with remarkable debulking, we performed an extended thymectomy combined with a left pleuro-pneumonectomy. Masaoka staging was IVa. All the resection margins were negative. Follow-up was negative for 5 years until an abdominal CT-Scan revealed a splenic mass of about 3 cm: splenectomy was then performed. Two years later, a PET-Scan found a bone metastasis in a lumbar vertebra; after radiotherapy, a CT-PET Scan showed a left paracholic hypermetabolic spot, surgically removed by omental partial resection . To date the patient is disease-free . Discussion: In advanced staged Thymomas, recurrences may occur in up to 50% of patients. Recurrence, if operable, should be surgical eradicated, offering good long-term survival. The exceptional nature of our case lies in the long disease-free period, in the site of the metastases and in the final outcome which was beyond all expectation.