[Chamberlain biopsy is not necessary when mature teratoma is evident on imagery]

Mature teratoma represents 60 % of germinal cells tumours of the mediastinum. Most patients with these tumours are asymptomatic, so the neoplasms are usually discovered by accident during routine chest X-ray examination. They have specific and almost pathognomonic radiological features. However, patients can be symptomatic and may present with chest, back, or shoulder pain; dyspnoea; fever; pleural effusion; cough; and bulging of the chest wall.

We report the case of a young woman presenting with a giant mediastinal mature teratoma compressing the left lung. The patient was admitted for dyspnoea and non productive cough. The chest X-ray showed a mediastinal mass and a chest computed tomography scan revealed a heterogeneous pluritissular mass lesion of the mediastinum. Complete surgical removal is the treatment of choice for mature cystic teratomas, with optimal results and an acceptable surgical risk. This approach allows confirmation of the diagnosis and is the only way to rule out the presence of malignancy. Surgical biopsy by the Chamberlain method is therefore not strictly necessary.

When chest X-ray and a computed tomography scan show specific radiological features of teratoma, a complete resection should be undertaken if the patient is fit for surgery. This will confirm the anatomico-pathological diagnosis, exclude the presence of malignant cells and it represents the treatment of choice of mature teratomas.