Haemorrhagic brain metastasis from a thymic carcinoma

Abstract

Brain metastasis from thymic carcinoma is extremely rare, and there is still no consensus regarding the best management of thymic metastasis to the central nervous system. Here, we report the first-known Australian case. A review of the current literature and the characteristics of thymic tumours with brain metastasis indicate that aggressive management may be able to improve long-term outcomes for these patients. A 49-year-old man presented 2 weeks after thoracotomy for thymic carcinoma resection with a 2-day history of headache, right-sided weakness and expressive dysphasia. CT and MR scans revealed two metastatic brain lesions, one within the left frontal lobe with cystic necrosis and haemorrhage, the other deep in the parietal lobe adjacent to the left ventricle with a lesser degree of haemorrhage. The patient underwent frameless stereotactic craniotomy for excision of the frontal lesion. Histopathology confirmed poorly differentiated thymic carcinoma. Post-operatively his weakness and speech improved dramatically, and he was discharged home within a week, with radiotherapy and chemotherapy to follow. However, he represented with rapidly worsening symptoms and died within a week. Thymic carcinoma is a rare tumour, displaying malignant features clinically and histopathologically with local invasion to adjacent organs. Metastasis is predominantly to lung, bone, liver and kidney, with less predilection for the central nervous system. Treatment for thymic carcinoma is multimodal, but outcome remains poor and life expectancy is very short when brain metastasis with haemorrhage is present.