Malignancy: A Rare, Important and Poorly Understood Cause of Priapism

Priapism in a patient with advanced hepatocellular carcinoma

“…Direct neoplastic cell invasion into the penile cavernous sinuses and venous system, resulting in the complete obstruction of venous outflow is the proposed mechanism. 2 Although malignancy-related nonischaemic priapism is rare, as was observed in our case, a case of non-ischaemic priapism secondary to unregulated arterial inflow without compromised venous drainage was reported in patient with metastatic bladder cancer. 3 Penile metastasis from HCC with an increased arterial blood flow was considered to be the most likely cause of priapism in this Figure 1 The finding of the patient's priapism.…”

Malignant Priapism – What Do We Know About It?

“…Over time, several factors involved in IP pathogenesis have been identified: benign or malignant hematological disorders (more frequently sickle cell disease (SCD), glucose-6phosphate dehydrogenase deficiency and leukemia), vasoactive erectile agents, recreational drugs, alcohol abuse, neurological pathologies (cauda equina syndrome, autonomic neuropathy, spinal cord injury/ tumors), metabolic disorders (amyloidosis, Fabry disease), antihypertensive medication (4), antidepressants, antipsychotics, anxiolytic drugs, antagonists of the alpha-adrenergic receptors and also malignancy. NIP is a less frequent type of priapism usually related to perineal/pelvic trauma, whereas RP is a form of ischemic priapism and has the same risk factors, but it is more frequently associated with hematological disorders (5)(6)(7).…”

“…The first mention of malignant priapism (MP) dates back to the beginning of the 20th century, when in 1938 Peacock described this type of priapism as a persistent erection, without any identifiable trigger factors that could lead to sexual stimulation. The mechanism proposed for this type of priapism was the invasion of cavernosal sinusoids and their efferent veins by malignant cells (5,8).…”

“…MP may as well be the result of a nearby pelvic or perineal tumor that extends and invades the penis and the corpora cavernosa. This scenario can be encountered especially in malignancies that affect the prostate, bladder, urethra, testicles and the anorectal region (5,12,13).…”

“…It is generally accepted that MP is an ischemic type of priapism, due to the fact that the main physiopathological mechanism implies direct cavernosal tumor invasion which affects the cavernosal sinusoids and their emerging veins, eventually causing their obstruction with the appearance of cavernosal venous stasis that leads to erection. Another possible mechanism for ischemic MP, but significantly less frequently encountered, is the tumoral infiltration of the neurologic pathways involved in the penile tumescence and detumescence process (5,12).…”