Thymic carcinoma--analysis of nineteen clinicopathological studies

Primary thymic carcinomas are rare tumours with nonuniform management protocols and poor prognosis due to delayed diagnosis and highly malignant behaviour. This review summarises the major clinicopathological studies to assess more fully the prognostic importance of tumour histology and staging as well as treatment benefit.

A Medline search from 1966 to date was carried out and relevant references gleaned from these. Nineteen clinicopathological studies form the core of this review. Demographic data and clinical features were examined in all studies. Correlation of outcome with histology was possible in fifteen of the studies and with tumour staging in thirteen.

Thymic carcinomas occur most commonly in the fifth to sixth decades of life, usually presenting with symptoms of space occupation or invasion. Paraneoplastic syndromes are rarely associated, except with the well differentiated thymic carcinoma. Of 140 thymic carcinomas, 40 were squamous cell, 19 were spindle cell and 16 were lymphoepithelioma-like. Completely resected stage I and II tumours demonstrated the best survival.

Complete surgical resection is taken to be the desired treatment, but the continued high mortality and relapse rates and the variable benefit of adjuvant therapies challenge this strategy.