Neoplasms of uncertain behaviour of thymus are rare tumours of the thymus, accounting for less than 0.5% of all thymic malignancies. The cause for these is unknown, but several theories suggest that genetic predisposition, environmental factors and hormonal imbalances play a role in their development.
Diagnosis is usually made with a combination of imaging tests, such as CT scan and MRI, and histological examination of a biopsy sample.
Differential diagnosis includes other tumours of the thymus, such as thymic carcinoma and lymphoma, as well as metastatic tumours from other organs.
Treatment often involves surgery, as well as radiation and chemotherapy. Surgery is typically used to remove the tumour, while radiation and chemotherapy are used to destroy the remaining cancerous cells.
The prognosis of neoplasms of uncertain behaviour of thymus is poor, with a median survival time of less than one year. Early diagnosis and aggressive treatment may improve the prognosis.