Calcium in Epidermoid Cysts

Apparently it’s not unheard of for epidermoid cysts to have little particles of calcium.

Now, the cheesy, sebaceous substance that fills the cyst makes perfect sense to me – it stands to reason that the blocked gland produces sebum, and various and sundry epithelial cells end up there as well. Add a few bacteria, some white blood cells, and you get the fetid substance that cysts normally have.

The idea that somehow the body deposits calcium there weirds me out, no end. Why would that happen?

Many chronic lesions in the body ultimately contain calcium or become calcified. A great example occurs in the lung, where the site of an old TB infection often becomes calcified. Same thing in the spleen, kidney, etc as a response to infection and other diseases.

BTW, you do mean epidermoid and not dermoid cysts, right? Dermoid cysts arise from precursor cells that have the inherent ability to differentiate into skin, hair, teeth, muscle, etc. Often, these type of things are found within dermoids. They often contain calcified matter like bits of bone and teeth.

This site shows an xray of a pelvis (2nd image on page). You will see a collection of teeth! This is a dermoid cyst.

Karl - I defintely meant epidermoid cysts – the things that are sometimes called wens or sebaceous cysts.

You’ve said that it often happens – I was hoping to delve a bit more into the why part. What process actually deposits the calcium there, and why?

Well, the answer isn’t completely clear (to me at least).

In part, the calcification process in things like cysts and sites of old infections, arises from the liberation of various phospholipids and phosphates from the membranes of dead or dying cells in the area. These substances are formed when certain membrane-associated enzymes are given free rein as a cell dies (i.e. the ensymes are normally inhibited but become activated as a default as the cell’s normal homeostatic machinery fails).

In any case, calcium has great affinity for the phospholipids and phsophates mentioned above. Calcification ensues.

As a lay person, I’d like to comment. Forgive me, Bricker, if this doesn’t apply to you, but many people are under the misconception that calcium is only found in bones and other hard substances of the body (such as kidney stones). However, calcium is found in all the cells of the body. I’ve known folks who say that adults don’t need calcium since their bones have stopped growing. That was a few years ago before the news of osteoporosis has been so wide-spread. But it’s not just the bones, and your body will rob the bones of calcium for more essential purposes if you don’t ingest enough. Again, I apologize Bricker if this doesn’t apply to you.

I’m no MD, but I suspect we are not really talking about deposits of calcium metal. It’s a rather reactive element. Perhaps it’s used as shorthand for some calcium compound such as calcium phosphate?

No need to apologize – although I did realize calcium was everywhere; what baffled me was the process or reason it “percipitated out” in cysts - why, in other words, did the cyst end up with actual calcium-type deposits as opposed to the more common, and effectively invisible, calcium elsewhere.

KarlG’s explanation, which he characterizes as only partial, is good enough for me, though - even though there may be some other process at work as well, what he said makes perfect sense…

  • Rick

Calcium ions. They are indispensable for muscle contractions and muscles are everywhere.

Yes, calcium phosphate in the form of an apatite. I believe the most common is hydroxyapatite.

As barbitu8 stated, calcium ions are ubiquitous in the body. In addition to their role in muscle contraction, they are essential for the functioning of essentially all membrane receptors in all the cells of the body.

Regarding phosphate, in addition to a normal background level in the circulation of approximately 1 mmol/L, massive quantities of phosphate moieties are liberated during cell death.

The production of calcium phosphate proceeds along physico-chemical lines, although there are some naturally occurring calcium binding proteins with strong affinity for hydroxyapatite that assist in mineralization