Intravascular large B-cell lymphoma or intravascular lymphomatosis: reportof a case diagnosed by testicle biopsy

Intravascular large B-cell lymphoma or intravascular lymphomatosis (IVL) is an extremely rare form of non-Hodgkin's lymphoma. The most common clinical sign is fever of unknown origin (FUO). Histologically, there is proliferat ion of malignant lymphoid cells within vascular lumina. Cytologically, the cells have features similar to those found in classical large cell lymphoma . Examination of pulmonary artery blood showed the presence of this abnorma l population in our patient; to the best of our knowledge there are only fo ur other reports of detection of circulating tumor cells in IVL. The outcom e is very poor. The diagnosis is most frequently made after biopsy of skin or brain but is often established post mortem. We present what is - to our knowledge - the first reported case of IVL diagnosed after biopsy of a test icle. In the event of FUO and suspicion of a malignancy, IVL - although ver y rare - should be one of the differential diagnoses.