All the Differences between Follicle and Ovarian Cysts ( Tests, ultrasound etc)

(Monday, July 21, 2014)

A patient just sent me this query

I am 29 and trying to conceive for the past 4 years. I have irregular cycles. My doctor prescribed me Injection recagon 100units for 6 days from 12-May-2014. On 11th day of the cycle during follicle study I got dominant follicles on both ovaries and doctor prescribed to take orgasmed capsules for 14 days This month I didn’t get my periods and HPT is negative and even checked with the doctor, it is negative again and she prescribed me registration tablets for 10 days I have a clarification. If I got dominant follicles on both ovaries, where the follicles would have gone? As per my assumption, it should be either fertilized or I should have stated periods. I'm so confused. Please guide me.

It’s very common for infertile women to be confused about reproductive basics. They often do not understand the relationship between the menstrual cycle and ovulation; or the difference between follicles and eggs; or how the follicles are different from cysts.

We need to go back to basics, to make sure there is clarity going forward. Otherwise, this poor patient will keep on going round and round in circles, cycle after cycle!

This was my answer.

The reason your periods are irregular is that you, Do not ovulate. This is called Anovulation read more here.

This may be because you have PCOD (polycystic ovarian disease) You can read more here.

You need the following medical tests.

1. Blood tests for you for the following reproductive hormones – To check the quality of your eggs. Do this from a reliable lab such as SRL (

  • FSH (follicle-stimulating hormone)
  • LH (luteinizing hormone)
  • PRL (prolactin)
  • AMH (anti-Mullerian hormone)
  • TSH (thyroid-stimulating hormone)

2. A vaginal ultrasound scan should check for the following.

Please send me the detailed test results and medical reports. You can scan them in as a single Word file and email them to me. Patients with PCOD will typically have a high AMH level; a high LH: FSH ratio; increased ovarian stroma; and many small cysts arranged around the periphery of the ovary.

So what’s the difference between a follicle and a cyst? A cyst is basically a follicle, which does not contain an egg. They both appear as hollow dark spherical objects in the ovary on ultrasound scans. Since we cannot make out if the structure we see about scanning contains an egg, this creates a lot of confusion in the patient’s minds.

To make matters worse, doctors often loosely refer to the follicles seen on ultrasound scanning as eggs. In reality, eggs are microscopic, and can only be seen in the IVF lab when the follicular fluid is examined under the microscope by the embryologist. While there are many kinds of cysts, the commonest kind we see is called a functional cyst, which looks exactly like a follicle, except that it’s larger.

Thus, when a mature follicle (which contains an egg) failed to rupture at the time of ovulation, it collects fluid and becomes larger. This is called LUF syndrome Read more here.

A functional cyst (so-called because it is functioning and produces hormones) will often result in the period being delayed, as a result of the hormones it produces. This is why it may cause the period to be delayed. It’s possible to make this diagnosis by doing an ultrasound scan. The period can be induced by medications. These cysts will usually resolve on their own.

Have a query you are scared to ask your doctor because he is too busy?

Please e-mail Dr. Malpani your reports and queries at
We are looking forward to helping you have a baby!

Authored by : Dr Aniruddha Malpani, MD and reviewed by Dr Anjali Malpani.