Thymic cysts are a rare abnormality accounting for 1%–3% of all mediastinal masses. In most cases, they are asymptomatic and localized in the anterior mediastinum. Despite their benign nature, the presence of a mass is an indication for surgery to obtain a histological conclusion and reliably exclude an oncological process. Epidermoid cysts are rare and only a few cases are described in the literature. In our case report, we present a rare case of examination and treatment of a patient with a large anterior mediastinum mass, which, according to the results of histology, was an epidermoid cyst of the thymus.

Adrenal gland incidentaloma (incidental – sudden, accidental) is a mass of the adrenal gland(s), accidentally detected by an instru-mental examination conducted for other reasons. The frequency of detection of this pathology based on computer tomography of the abdominal organs is 0.5%–2%. In most cases, the mass is represented by adrenocortical adenomas without hormonal secretion. It is an extremely rare case (less than 1% of all cases) when the adrenal incidentaloma is a primary adrenal lymphoma, which accounts for 1% of all non-Hodgkin lymphomas and 3% of all extranodal lymphomas with a few cases reported in the literature. In our article, we present a case of left adrenal incidentaloma of the adrenal gland, which, during further observation and examination, increased in size, which was the reason for performing laparoscopic adrenalectomy. According to the results of the histological examination, the mass turned out to be diffuse large B-cell lymphoma.