Squamous Cell Carcinoma of the penis
A call came in for a horse that had suddenly presented with a swollen sheath. The gelding could urinate ok although he never normally dropped his penis to do so. The horse’s clinical examination was unremarkable and his sheath was moderately swollen. He was sedated into the vein with a combination of sedatives which included ACP. This drug increases the chances of them dropping the penis.
Once the gelding had dropped his penis it became apparent what the problem was. He had several cauliflower-like growths on his penis which were highly suspicious of a squamous cell carcinoma. This is a slow growing locally invasive tumour affecting the penis amongst other places.
A punch biopsy was taken of one of the lumps and put in formalin. This was then sent to the laboratory for analysis to confirm the suspicion. The results of the histopathology report were as follows:
There are various treatment options for a scenario like this:
- Partial penile amputation
- Full penile amputation and perineal urethrostomy
- Benign neglect (choose not to do anything)
It depends on a number of factors as to which option is done. If the tumour is localised only towards the tip of the penis then partial amputation of the penis under general anaesthetic is an option. If it affects the whole of the shaft of the penis then complete amputation and perineal urethrostomy can be carried out. This lengthy procedure involves the urethra (tube that the urine comes out of) being directed under the anus and an opening being made so that the gelding will now urinate like a mare. Cost and age of the horse also has to come into the equation when making any of these decisions.
As long as the gelding isn’t in any discomfort, antibiotics and painkillers can be given in the short term until such time as the tumour does cause more of a problem in which case a decision of euthanasia can be made. Each case should be taken on its own merits as they all differ.