The weird world of ovarian dermoid cysts

Well, I did call this blog ‘multifaceted’…

I’d never heard of teratomas or dermoid cysts until April, when I was diagnosed with a large cyst on my left ovary during investigations after I suffered a massive pulmonary embolism out of the blue with no known risk factors. [side note: the NHS is amazing and saved my life – thanks Lewisham Hospital]

The gynae doctor who gave me the diagnosis sensibly told me enough to stop me doing too much online research – basically it is a type of cyst that is almost always benign and is made from a variety of tissue, most commonly including skin, fat and hair but often also bony material. Around 10-13% of ovarian tumours are dermoid cysts (source).

Once I was on the mend I did do some cautious research of course (I am a librarian after all) but didn’t delve too deeply until my cyst was removed at the end of July. I found I could stomach (sorry) the whole topic rather more once I knew there wasn’t a cyst pressing on my internal organs and blood vessels in a potentially life-threatening manner, and had an incentive to do research as friends and family had lots of questions – how big was it? How much did it weigh? How long had it been there? Where on earth did it come from?

Once I’d learned enough to have a go at answering those questions, I thought it only right to share the fruits of my brief literature search with the wider world. I hope you enjoy my little annotated bibliography safe in the knowledge that you’ll only see disgusting images of cysts if you click through to links that I’ve indicated have them – an advantage of my list over researching this topic via a search engine or Wikipedia!

Read to the end for the most clickbaity journal article title I’ve ever seen; to my great surprise the payoff was justified.

[and yeah, I have been very lazy and not made proper citations, sorry folks…]


Management of giant ovarian teratoma: A case series and review of the literature
[includes images if you scroll down enough]

On reading this I learned that my cyst was officially GIANT (20cm – giant cysts are anything over 15 cm). 30% of people with giant cysts did not report any symptoms [I hadn’t really noticed anything before my embolism]. This article focuses on how to manage giant cysts (basically whether to remove via keyhole surgery or open surgery) but has some useful general info too and some slightly gross images.


Mandible like structure with fourteen teeth in a benign cystic teratoma
[links to images at end but not embedded]

Ok, so this is maybe the time to disclose that when the doctors opened up my cyst they found a small malformed jawbone with five teeth on it. From the scans I’ve seen I think they look like premolars or molars which tallies with the article on teeth below. The doctors were pretty gleeful when they told me about my cyst (having checked I wanted to know!) as none of them had seen a jawbone in one before, including the head of the department!

Anyway, the patient in this article had similar cyst contents to me (14 teeth on a jawbone plus the usual other stuff). Their cyst was slightly smaller (18 x 16 x 15 cm) and weighed 1.8kg. So my best estimate is that mine weighed around 2kg, and this seems about right based on my own weight loss since the cyst was removed.

Growth rate

The growth pattern of ovarian dermoid cysts: a prospective study in premenopausal and postmenopausal women

Typically *very* low in the group studied (mean average 1.8mm a year, highest 16.8mm a year) but this is a study which excluded any cysts growing at over 20mm per year so is not terribly helpful.  My cyst must have grown much faster than their average rate else I wouldn’t be old enough to have one that size.


Ovarian Mature Cystic Teratoma Containing Homunculus: A Case Report
[link is to abstract; article PDF includes images]

“Despite a number of conflicting theories (7-10) to explain the histogenesis of teratomas, the most probable ones are misplaced blastomere and parthenogenetic development of a germ cell.”

A blastomere is a cell originating from division of a fertilised egg. Parthenogenetic development is basically asexual cell reproduction (I think of it as an unfertilised egg going rogue) and seems to be the dominant theory.

I can’t really move on without mentioning that this article discusses a fetiform teratoma ie a cyst containing a homunculus, something with enough differentiated and organised tissue to resemble a human form. Around 24 had ever been reported at time this article was written. *shudder*

Pulmonary Embolism and benign cysts

Suprarenal vena caval thrombosis and pulmonary embolism associated with a benign ovarian cyst
[first page only; includes scan images]

This is the only article I could find that documented a PE caused by a benign ovarian cyst but for all I know it may not be unusual enough for articles to be written about it. There’s no evidence I had a thrombosis in my vena cava as I had typical DVT symptoms (calf pain) before my PE.

Unusual cyst contents

Dental structures in benign ovarian cystic teratomas (dermoid cysts): A study of ten cases with a review of the literature
[abstract only]

This article looks at teeth found in dermoid cysts and found they are most often pre-molar or molar. Generally neither baby nor adult in form but between the two.

“The teeth within a tumor tended not to form normal morphologic sequences. It is concluded that dental structures in ovarian teratomas are products of normal genetic/epigenetic events modified to a greater or lesser degree by unknown factors in the tumor environment.”

Benign Mature Cystic Teratoma Mimicking Normal Mandibular Development
[includes images]

“the excised teratoma showed a well-formed mandible with bone, teeth, skin, and hair”

Giant mature ovarian cystic teratoma including more than 300 teeth
[abstract only]

300? Really?! That’s just showing off.

Lactating breast tissue in benign cystic teratoma
[abstract only]


Benign cystic teratoma of ovary containing a homunculus
[includes very grainy images]

Another homunculus aka fetiform teratoma.

And finally…

Unusual dermoid cyst with surprise
[abstract only, includes photo; my god what a photo]