Follicular Cyst (often erroneously called Sebaceous Cyst)

[Lynx]

I noticed a small lump developing near Snowflake's genitals that gradually got larger over a few weeks until it was about 3/8" across. I assumed it was a trichofolliculoma as she'd had a probable trichofolliculoma removed six months earlier. That one had seemed flatter and I think she was biting at it (a scab that didn't heal). Due to the troublesome location of the new lump and fact that it was not scabby, I figured I'd wait some. Four days ago, I decided to take some pics with the intention of showing them to my vet -- to find out what he advised due to Snowflake's age and the awkward location (how easy would it be to remove).

These are the pics I took:







I think it had been smooth on top and the wrinkled skin(?) on top was new.

Yesterday day I looked at it and found it had changed radically -- it appeared a white, sebaceous material [correction: probably keratin, not sebum] was inside an enlarged pore -- I scraped some off with my fingernail to get a better look (maybe Josephine or Mel can tell me if I have to clean it out well or what).

Here's what it looks like now (pics taken this morning):





And here's a pic taken 12/10/05 showing what it looks like after my carefully picking out the most visible part of the [probable] keratin. I used a dull slightly curved tip dental tool with no squeezing to remove the easiest part:



Snowflake has had a skin tag behind her ear (now gone, I think) and the probable trichofolliculoma that was removed surgically during the summer. Other possible causes of lumps are fatty lipomas and abscesses. This lump was not warm to the touch and did not appear at all to be an infection. I didn't want to break the skin to see what was inside since if it had been a trichofolliculoma, it would have merely been fibrous tissue (I didn't want to introduce a route of infection). Looking at the top pic, one can now see the thinning of the skin over the sebaceous material [correction: probably keratin, not sebum].

I hope these pics help somebody.
Generally, we recommend checking out all lumps. Don't make the mistake I made of assuming new lumps are the same as old lumps.

[Brandilynn]

Thanks for those good pictures Lynxie. Poor Snowflake and her lumps!

[Lynx]

I feel I am very fortunate to have gotten the pics before the skin cap dried up and came off. In the third pic, it looks like it is starting to separate.

[lisam]

I can't wait to hear Josephine's recommendation. Are you still going to show your vet? My Beru has one of those on back, but she's a texel and her long hair keeps it well covered. Periodically it opens up and I gently squeeze the material out (twice a year or so). I'm wondering if Josephine will recommend having Snowflake's removed, because of the position (perhaps more chance for bacteria). Remind me of how old she is?

[Lynx]

She's 6 and a half. I'm not likely to have it removed (cost and age) unless it ends up being a problem. From what I understand, they can be removed in their entirety and that's the only way to prevent them from recurring.

The material is pretty stiff and I would have to squeeze too hard (in my opinion) to get it out. It's kind of waxy. I scraped some out but don't know the best way to clean it. Maybe soaking in warm water would help? Would one use a loop of some sort to scrape it out? I don't think it would flush out.

Note: in dark skinned guinea pigs the sebaceous material would likely be varying shades of gray. It's white in Snowflake only because she has light colored skin.

If anyone else can describe this type of cyst on their guinea pig (location, size, color, how you treated it), please do.

[whittibo]

WOW, those are awesome pictures Lynx!

Of course I have no clue what it is, I wonder if piggies get "acne" or closed pores?? (my first thought was it looked like a big pimple?!)

Does it bother her for you to touch it?? It certainly doesn't look infected at all.

[Mum]

This is similar to what Goldie had on her side a month ago, but as she's dark skinned it appeared as a small lump on her side. The vet said it was a gland that was filling up. When I took her to the vet, he squeezed it and dark skin-like material oozed out - it was very thick. When totally emptied it left a hole into which I squeezed Otomax to keep it from getting infected. It's now healed up. The vet said it will keep coming back and removal would be the only prevention - but there was no need to do this. It never bothered her (except when squeezed).

Also, he didn't need to lance it - and I forget why. He did something that had the same effect, and then he was able to squeeze it (pretty hard, I might add). Otherwise he would have lanced it. She squealed when he was squeezing it, of course.

[whittibo]

Gosh mum, that sounds like a pimple/zit doesn't it?? Very odd. Maybe even an ingrown hair?? The poor thing, I can't imagine squeezing it out, it's huge! :s

[lisam]

Beru does not like me to touch hers at all, it probably does hurt a bit when I squeeze, which is why I'm gentle and I do it rarely. I only do it when it pops open itself. It leaves an open area, like a pit. Just before it opens up it's about 1cm diameter. The material is thicker than pus, and creates a hard "crust" on the top.

I only do this because the vet recommended it after I took her in the first time I discovered it. The sebaceous material in Beru's is a greyish color, since she is a tortoise shell and has black skin. Beru's is in a better place to have it removed, but she's an older pig as well.

I would not recommend that anyone try squeezing one on their own without first seeing a vet.

[CavyAnnex]

Ally has something similar but in a different location (on her back).

The vet said that there isn't much that can be done; she could have surgery, but it's unnecessary unless it starts to bother her or if it gets really big.

The vet told me to squeeze it every couple of weeks and to make sure I kept it clean so that no infection developed.

I have noticed that it has gotten bigger since I first spotted it.

[Lynx]

I think the second set of pics illustrates the "pit" like look you likely are describing (right?).

Merck says not to squeeze it:

http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/72206.htm
General advice on Keratinized Cutaneous Cysts:

"Vigorous squeezing of these lesions is contraindicated because it often incites a severe foreign body inflammatory response.

"Infundibular follicular cysts (epidermoid cysts, epidermal inclusion cysts, often erroneously called sebaceous cysts) are the most common ... they are filled with a gray, brown, or yellowish, granular, “cheesy” material that is lumenal keratin"


[EDIT: the links below are dead because accuvet is no more -- Lynx]
Laser treatments:
http://www.accuvet.com/pdf/sebaceous_cyst_technique.pdf

From general area showing lots more laser treatment techniques:
http://www.accuvet.com/content/small_avian_exotic_cs

[Josephine]

I would at least have it checked out. Infection is probably the most significant complication to something like this that appears otherwise benign. It doesn't look like an abscess, for sure.

Oh, and it DOESN'T look like a sebaceous cyst.

[Lynx]

You don't think so? What would the waxy material inside be?

[Mum]

I was told the waxy stuff was glandular material.

[Josephine]

Yeah, keratin.

There are many types of cysts. Sebaceous cysts are only one type. Many are benign, but they can get secondary infections.

[Lynx]

Then I'm still on the right track, no? I quoted this from Merck:

"Infundibular follicular cysts (epidermoid cysts, epidermal inclusion cysts, often erroneously called sebaceous cysts) are the most common ... they are filled with a gray, brown, or yellowish, granular, “cheesy” material that is lumenal keratin."

So, not sebaceous cyst but a follicular cyst filled with keratin then.

How would you have removed the keratin?

[Josephine]

Yes, on the right track. It's just not "sebaceous," although that term can be a blanket term for anything having to do with the skin. Sebaceous cysts are generally much larger. And grosser! (Like my command of the English language?)

Remove them surgically. Sometimes vets will drain with a needle or they will rupture, reform, and cycle through a rupture/reform cycle.

[Lynx]

I found a cool pdf with a laser technique for removing them -- they pull out the "wall".

http://www.accuvet.com/pdf/sebaceous_cyst_technique.pdf

It's so thick that I don't think draining would do any good.

[lisam]

Oh, thanks for the information, Lynx. I'm sure Beru will be very happy to know I won't be squeezing it anymore.

What kind of animal is that they are using that laser procedure on?

[Lynx]

I don't know. Neat pics though, no? It looks like they grab the material with a forceps and pull it out. I wonder if we could do that? Perhaps a very narrow tweezers?