A few points about excising sebaceous cysts for trainee surgeons
Often this task is left to the junior registrar in the public hospital on minor procedure list with little supervision ..these are a few tips.
1. Terminology: Depending on location – they are more likely epidermal/epidermoid cysts or pilar cysts.
2. A cyst can certainly get infected – I have seen green pus amongst the cheesy white keratinous material (and it can certainly smell!). If there is a lot of induration – it may be best to just drain the pus and keratin material first.
3. If the cyst has recurred because part of the wall has been left behind, then the cyst may not feel as tense as a normal cyst. It will feel boggy and soft.
4. The cyst can be easily excised with the wall intact – local anaesthesia is used to hydrodissect around the cyst as well as for anaesthesia. Care must be taken not to let the fluid squirt out through the punctum! (no problem for the patient – but more for the surgeon and the assistant) A small incision is made right down to the wall of the cyst – care must be taken not to cut into the wall. Then a fine artery forceps can be used to dissect the cyst off the surrrounding tissue. The cyst can then be squeezed out throught the narrow incision …usually intact.
5. If a cyst has been been knocked or inflammed, then it may not be as easy to remove the cyst. Sometimes, the wall has be be excised with a scalpel.
These are relatively common in surgical practice. Despite having done lots of these, I still find the occasional challenging ones which are hard to excise. And it is not always possible to remove the wall intact.