Rare thymic malignancy of B-cell origin - T-cell/histiocyte-rich large B-cell lymphoma

Aim: T-cell/histiocyte-rich B-cell lymphoma is a rare type of diffuse large B-cell lymphoma reported as involving primarily the thymus only by one paper in the English literature. Case presentation: A four and a half years old boy was admitted, after a sudden onset in the middle of the night, with superior vena cava syndrome, resuscitated cardiac and respiratory arrest and severe coma with Glasgow Coma Scale rate of 3. In spite of intensive treatment, the patient repeated twice the cardiac arrest and died sixteen hours after admittance. The autopsy confirmed the existence of a huge mediastinal mass, revealed by the prior to death computed tomography examination, and the thorough histopatological established the diagnosis of T-celVhistiocyte-rich large B-cell lymphoma of the thymus with renal spread. Discussion: The particularities of the presented case are the primary location of the lesion in the thymus, the age of the patient, very young, the lack of lymph nodes involvement and the rapid development of the disease until death without any possibility of therapeutic specific intervention. Conclusions: The case is the second reported in the literature with primary involvement of the thymus by this rare variant of diffuse large B-cell lymphoma. The histopatological examination is the golden standard for the diagnosis. Any clinical symptom of unexplained fatigue and dyspnea in a child should raise the clinician's suspicion of a mediastinal mass involving the thymus.