[Priapism following paraneoplastic leukemoid reaction in a patient with bladder cancer].

Priapism associated with solid tumours is usually produced by penile metastasis or direct tumour infiltration of the corpora cavernosa. Neoplasias are responsible for between 3-8% of all cases of priapism, and in 80% of cases the primary tumour has a genito-urinary origin. Leukemoid reaction is an haematological disorder characterised by a leukocytosis of over 50000/microl, which develops reactively with different pathological processes such as severe inflammation, disseminated infections, intoxications and tumours. The pathophysiologic mechanism that explains priapism following leukemoid reaction is an intravascular obstruction due to blood hyperviscosity, leading to a blood stasis in the cavernosa veins, and impeding the drainage of the corpora cavernosa. We present a case of priapism in a patient with locally advanced bladder cancer, which was probably the result of blood hyperviscosity produced by a paraneoplastic leukemoid reaction.