A 29 year old patient attended the Emergency Department of our Hospital with a mildly painful erection of ten hours' duration. The patient reported having had four similar episodes in the last three months, but in all of them the erection had subsided within three to four hours at most.
The patient denies any history of penile trauma, the use of drugs or other medication, including intracavernous injections. There were no other accompanying symptoms such as asthenia, anorexia or fever.
Blood gasometry was performed on the blood taken from the corpora cavernosa, obtaining analytical results for venous blood (pCO2 163.1 mmHg, HCO3 13.2 mEq/l plasma).
Given this priapism of prolonged duration and the absence of signs of high-flow priapism, we proceed to try to reverse the erection as soon as possible, in order to calm the pain and avoid irreversible damage to the corpora cavernosa.
A 19 G intravenous catheter is punctured in both corpora cavernosa, blood is repeatedly aspirated and allowed to drip out. After this first step, no decrease in erection is obtained, so a solution of phenylephrine (alpha-adrenergic agonist) is prepared in saline at a concentration of 0.1 mg/ml. Two ml of the solution is injected into a corpus cavernosum and then compressed. This manoeuvre is repeated again in the contralateral corpus cavernosum. If there is no response, a new phenylephrine solution is made by mixing 10 mg of phenylephrine in 11 mg of saline and 20-30 ml of this solution is injected into each of the corpora cavernosa to wash them. After repeating this last manoeuvre several times, penile flaccidity is finally achieved.
During his stay in the emergency department and after achieving flaccidity, blood tests were drawn and revealed a marked increase in the blood leukocyte (414 x 109/L) and platelet (1100 x 109/L) counts.
Suspicion of a myeloproliferative syndrome led to consultation with the Haematology Department, which diagnosed chronic myeloid leukaemia.

The patient subsequently underwent an allogeneic bone marrow transplant from an HLA-identical family donor. The evolution of his haematological disease was favourable and the priapism was completely resolved with the treatment of the chronic myeloid leukaemia and without alteration in sexual potency.