This is written with the aim of helping my medical students and doctors in training go through my thought process in the outpatient clinic. This list is not meant to be all comprehensive but rather a practical guide in coming to a diagnosis quickly.
1. Duration – has this lump been there for some time and growing slowly (most likely epidermal/pilar cyst)
2. If the lump is of recent onset and is painful – consider if that could be an inflammed epidermal cyst or abscess
3. Lymph node – especially in back of scalp eg occipital lymph node. An US can be helpful if the lump is large – to see if the normal lymph node architecture is present or absent. In case of the latter, consider US-guided FNAC
4. Have a look : if subcutaneous – epidermal cyst. But also to consider lipoma especially at back of scalp. The pilar/epidermal cyst usually has a punctum – but that may not be easily seen(although when you inject LA into the lump, you can sometimes see a bit squirting out) Because of the thick skin, it can be difficult to differentiate a lipoma from a cyst.
If on the skin – consider – skin cancer eg melanoma, BCC or SCC. (I can recall a sad case where a young woman in her 20s presented with a large nodular melanoma on the scalp with satellite nodules – this was discovered by her hairdresser )
5. Other rarer causes – osteoma (bony tumours of the scalp), other soft tissue tumour, tricholemmal cyst
Management:
Offer excision under local anaesthesia – to remove the lump. Best to use an artery to dissect bluntly in the plane around the cyst wall if possible. The Local anaesthesia is also good at helping in creating a plane between the cyst and the surrounding tissue(a bit of hydrodissection). Be careful when injecting in LA or when you incise a cyst that is tense with local anaesthesia – the LA may just squirt out (together with some sebaecous material that may not be smelling all that good…think months of accummulated dirt under the armpit) I always send the lump for histology. If lipoma, it is important to exclude the rarer spindle cell variant which can be more likely to turn to a liposarcoma. Make sure too to remove all the pseudopodia of the lipoma to reduce the risk of recurrence.
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.
Leave plastic waterproof dressing on for 1 week
If steristrips used – they can be left on for a further week.
If non-dissovable sutures used – they need to be removed usually in 1 weeks time, may be left in longer in certain areas where there is higher risk of the wound pulling apart(eg lower legs, back), can be removed earlier from face(eg 5 days postop)
Answers to FAQ:
1. Showering – you can shower anytime if waterproof dressing is on. If there is no dressing eg sutures on the scalp – best to keep that area dry for 1-2 days.
2. Bleeding – If a cyst/lipoma has been excised, the residual cavity will initially fill with blood-stained fluid(haemoserous fluid – this can have the colour of red wine). This can sometimes leak out from the wound. So be careful if you lie on the wound – it might be a good idea to have a towel under to soak any discharge. If there is a lot of thick red blood or pain from a hard swelling under the wound – you must contact me again.
3. Pain – The wound can be sore eg like any cut. The local anaesthetic usually lasts for a couple of hours. Paracetamol is usually all that is needed after that. If still in pain , consider adding something stronger like Ibuprofen(please from that there is no contraindication). If the pain is severe or the wound becomes painful after a few days (and there is surrounding skin redness) – please contact me
4. Work – most patients can go back to work the next day. But it is important to keep the surgical area clean.
5. Swimming – best not to swim in a public swimming pool until the wound is fully healed. After the sutures are removed, one should wait a few more days until the stitch holes are fully sealed over. (same applies to water sports eg in the Murray – best not to let the unhealed wound get into contact with water)
To prevent wound breaking open/scar getting wider after the sutures have been removed: sometimes it might be neccessary to reinforce the healing scar with Steristrips or even simple Bandaid. Also you should apply more sunscreen to the scar especially in the first 12 months to avoid the scar getting sunburnt.
LP Cheah
Surgeon
MelbourneSurgery.com
This can sometimes be tricky.
Cases I have seen include:
1. Removing a box thorn embedded deep in the tissues
2. Metallic foreign body – located by the use of a magnet; not always possible to remove it – especially if it is deeply located; sometimes one has to use an image intensifier in theatre, this is often an injury from work-related cause(eg miner in Broken Hill, apprentice on first day at work with mechanic; worker in factory)
3. Deeply penetrating large splinter – part of it was initially removed at a major trauma centre, patient was referred to me weeks later as persisting pain and granuloma. On exploration, 4cm remnant of penetrating splinter found and removed
(It is not always possible to remove every single fragment especially if friable object)
4. Spines of fish – this can be very hard to find, sometimes can be radioopaque
5. Broken glass – again also can be hard to find, I would say it is sometimes harder than looking for a needle in a haystack! But is it often satisfactory to be able to find the broken fragment.
6. Splinters, rose thorns etc
Sometimes by the time I am referred, a small abscess has formed around the foreign body – then it is easier to incise over the abscess, drain the abscess and remove the foreign body.
Reminder for residents:
Check tetanus status
Consider oral antibiotics treatment
Xray can be helpful to the surgeon ?radioopaque – some glasses are
Preauricular sinus
What is it?
There is a dimple or pit in the skin in front of the ear. From here a tract heads under the skin. This tract may or may not branch out. Frequently, the tract ends up being infected leading to redness of the overlying skin and a purulent discharge.
Why does it occur?
During foetal development, different parts of the head(called branchial arches) join together. Failure of this may lead to congenital problems such as cleft lip or cleft palate. In a similar fashion, the preauricular tract is due to different parts of the head not fusing together completely during foetal development. Occassionally, there may be other associated anomalies for example in the kidneys.
Treatment
When acutely infected, antibiotics is required. Sometimes if there is an abscess, this requires drainage. If possible, this should be drained by enlarging the pit opening and the tract washed out with Betadiene.
Surgery is the definitive treatment if there has been previous infections. This involves excising the whole tract and is best done in an operating theatre. Often the tract needs to be identified by injecting it with a blue dye. There is significant risk of recurrence with surgery(rates published are as high as 15-40%) – usually this occurs when the tract has branched and the the other tract has not been excised. Sometimes more radical surgery is required to excise out all the tissue in front of the ear to prevent recurrence and this would required a general anaesthesia.
Risks of surgery
Scar
Wound problems – infection, discharge, ooze, redness
Pain
Bleeding, bruising
Nerve damage – the facial nerve lies close
Recurrence
Often in my practice, I am referred patients with chronic warts that have failed other conservative measures.
Examples:
Warts in foot – often because of the long duration, the roots of the warts are digging deep into the sole causing pain on walking
Warts in fingers and palms
Warts on the nostril, around the face
Treatment options
1. Cryotherapy – liquid nitrogen. I often find it useful to consider this option first before considering surgery. For cryotherapy to be effective, the roots of the warts need to be frozen off as well. This requires a more prolonged application of the liquid nitrogen and often several repeat freeze-thaw cycles. The benefit is that it avoids surgery and leaves less scar. Risks with cryotherapy – discomfort and pain on application, blood blister(this can form after but the benefit is that the wart will usually fall off with time). Cryotherapy also needs to be repeated several times for it to work especially in chronic warts with deep roots. Once the warts resolves, the area may be darker or lighter than the surrounding skin.
2. Surgery – excision with scalpel or diathermy. This is more painful and requires either a local anaesthesia or general anaesthesia. Risks – the smoke from the diathermy may contain carcinogens(and be potentially infectious); surgery will cause bleeding and leave a scar.
There are few varieties of these including sebaceous cysts, epidermal cysts and pilar cysts.
What are these?
These are lumps under the skin. Occasionally one can find a small punctum(opening) on the overlying skin(You might be able to see more easily this if you pinch the skin to dimple it). The cyst is lined by wall and it contains white cheesy material. Common sites include the body and scalp. There can be more than one present.
What happens to the cyst?
The cyst will usually enlarge with time – the largest I have seen on the scalp measured about 15cm wide!! Sometimes, the lining will burst. This will lead to an inflammation in the surrounding tissue and overlying skin. This is often mistaken for an infection and treated with antibiotics. Rarely, the cyst can become infected primarily. It is best not to lance the cyst as this will cause scarring and make the surgery to excise the cyst completely more complicated
What other conditions can mimic a cyst?
Lipoma – esp if the overlying skin is thick, can sometimes be hard to distinguish
Other soft tissue tumour
What treatment is needed?
Surgery is usually recommended. Local anaesthesia is injected around the cyst. An incision is made over the skin. The cyst wall is carefully dissected(often best with an artery forceps) and the cyst removed with its contents. The wound is closed with sutures – usually non-absorbable. These are left in for 7-14 days. A waterproof dressing is usually used to cover the wound.
What are the risks of surgery ?
1. Wound problems – scarring, infection, breakdown
2. Recurrence – sometimes a fragment of the cyst wall is stuck down in the surrounding scar tissue and the cyst may regrow.