Traitement des tumeurs épithéliales thymiques

[Lymph node supraclavicular metastasis of thymic carcinoma: an inaugural and unusual feature of a rare disease]

Among the epithelial tumours of the thymus, thymic carcinomas are rare, involving more aggressive locoregional behaviour and a poor prognosis. More than one-third of cases present lymph node metastasis during an evaluation of the extension of a primitive mediastinal tumour of thymic origin. The authors report an unusual case in a 46-year-old woman presenting a metastatic form. The diagnosis of epidermoid thymic carcinoma was based on the histopathological examination of a right supraclavicular lymph node, associated with an anterior radiological mediastinal tumoral syndrome, raising the delicate problem of its diagnosis and treatment.

[Epithelial tumours of the thymus]

Epithelial tumours of the thymus include thymomas, thymic carcinomas and neuro-endocrine tumours. Rare, they nevertheless represent 20% of all mediastinal tumours and 50% of those located in the anterior mediastinum. Thymomas, in particular, can be associated to auto-immune disorders, among which predominates myasthenia gravis. Their clinical behaviour varies widely, from a relative indolence to the potential of lymph node and/or systematic metastases. However, even patients with an invasive disease may have a long clinical history, explaining that a 10-year or 20-year survival from diagnosis does not imply a definitive cure. In daily practice, both the clinical Masaoka's staging system and the WHO histological classification condition the treatment strategies and allow to anticipate the prognosis. The initial treatment, as well as that of the recurrence, is based mainly on a complete resection. Postoperative radiotherapy is systematically added to the treatment of invasive tumours and/or to those with an aggressive histological subtype. Inoperable or metastatic tumours require a cisplatine and anthracyclin-based chemotherapy, followed by radical surgery and/or radiotherapy.