Bony lump on 10 month old baby's skull

[AnaV]

Just wondering if anyone had a similar experience, I'm worried sick about my little one. My DD is 10 months old. When she was a few months old I noticed a hard lump on her head, solid as a rock, not moving. The lump is on the left side, at the bottom of the base of her skull, from looking at skull anatomy online it seems to be located at the ridge at the bottom of her occipital bone (image attached, I tried to label where it is). We went to the GP, they said it's just a "protrusion" as bones are still developing, it's just how her bones are at the moment and may disappear. This reassured us for a while but the lump didn't disappear and seemed to get bigger.

We went to GP again when she was 7 months old because I was uneasy with the lump still being there, and they said the same, the GP even made a nasty comment "well we'll just have to chop your head off" - the little one started screaming immediately at that comment as if she understood exactly how mean it is. This was obviously directed at me to tell me I am paranoid. She said she agrees with the initial assessment, it's just a thicker bone, a "protrusion". This was in August.

Today, when playing with DD I felt the lump again and immediately was overwhelmed with a sense of panic. Under my fingers, this doesn't feel as if it can be a normal part of bone development. It grew in size (now it's like a kidney bean, oval shaped). I googled again "protrusion" and this is a normal part of the skull in the middle of occipital bone, not on the side like my DD has. I felt like vomiting. I submitted an online request to the GP to be referred to pediatrics asap, and got an appointment with the GP on Monday.

Has anyone had a baby with a similar, bony lump and what was the cause? Are there systems in place to insist on pediatrics referral if the GP is as dismissive as the last two times? How can they know it is nothing serious just by touching it? Finally, if they are dismissive again, where can I take her privately - what specialty would this be under? We are an hour away from London so anything in the area would work.

I've been constantly worried about this but today something tipped me on the side of panic.

I took my son to an osteopath who could do cranial work for reassurance and it was a bone, due to development and how they fuse sometimes they can stick out. He told me skulls aren't symmetrical and can form this way. That may be an option for you for some reassurance. I hope all is well, I know the panic x

You have an image of an adult skull. I would suggest you look at the images of infant skulls. There are actually two matching protrusions at the base of infant skulls on the left and the right just behind the ears. These are the mastoid processes which protrude quite a bit more in babies than in adults.

They can get infected as part of a middle ear infection, so if one side gets swollen and red, then you should ask for the baby to be checked for mastoiditis.
https://www.nhs.uk/conditions/mastoiditis/

Adding a photo of mastoiditis in a baby in case it helps you visualise and compare to the bump you are feeling.
link because the screenshot is ‘under review’
https://aneskey.com/ear-nose-and-throat-conditions/

Thanks for the replies, indeed I couldn't find a good sketch of infant skull but point taken the lump may correspond to a different bone area in an infant than what I marked on adult skull. The point is, it is at the "edge" of the skull.

I don't think there is any chance my DD's lump is mastoiditis - the lump is part of her bone and it is not red or associated with any other obvious inflammation. It's also a lot further from the ear than on that image. She's also had the lump for over 7 months now (that we have noticed) so that probably excludes it too.

Ok, but you do realise in your image you literally circled in red the mastoid process?

Sorry I haven't realised that. It is difficult to see on a 2D image. I found this image of a baby with mastoiditis online, and circled where my baby's lump is in comparison - it's further back on the skull, not on the side. She has no swelling or bumps next to the ear.

Ok, well the good news is that the bump isn’t likely to be a mastoid infection- which like any ear infection can be cured with a course of antibiotics.

In the new image, you’ve circled about where the styloid process would be.
https://otosurgeryatlas.stanford.edu/otologic-surgery-atlas/surgical-anatomy-of-the-ear/overview-of-temporal-bone/#iLightbox%5Bgallery_image_1%5D/3

The mastoid and styloid processes both grow and lengthen during infancy and childhood. The styloid does tend to grow faster than the mastoid so seems to protrude a bit more until school age.

The GP should be able to gently feel your DD’s skull and tell if it’s normal.

My son had that when he was a baby, doctor said it was perfectly normal! It’s now gone

Take him to get it checked just in case, but I’m sure it’s fine!

Yeah it’s surprising how many lumps and bumps are on a normal skull. A lot of these become attachments for our neck ligaments. So we can hold our heads up.

These links are very helpful to orient myself in relationship to different bones, thanks!

I don't think it's stiloid protrusion either, ive tried to label on the image attached where I think the lump is (admittedly this is again adult skull but couldn't find infant one with stiloid labelled for comparison). Stiloid is labelled in red, I think the lump is on the bone where I circled yellow (or possibly green one if that one is in the position of yellow region in infants).

Forgot to attach image.

I guess wait for the GP appointment. I hope it’s normal. It’s always better to get it checked than not. So while trying to reassure you whatever it is it is likely normal or an easy thing to treat, I’m also not saying it’s nothing or to ignore it. I’d definitely show the GP any asymmetry between left and right sides.

But how can they exclude by feeling the skull if it is something else, like some forms of cancer - although rare, chordoma or Ewing sarcoma can appear in this region of the skull if I understood well. In the case of babies you don't want to leave this to "feeling the skull"?

Also my baby's lump doesn't feel just like thickened bone but an unnatural addition to it - it is oval and propping up from the bone, can this still be normal?

Well, they have to weigh up the risk of X-rays or MRIs or CT scans on infants vs a physical check because all the scans increase risk of cancer and have potential side effects. It might be a measure and monitor thing. Or a biopsy thing.

Could it be a lymph node? My son has these in the exact place you’ve circled and they’re oval shaped

Not really, because lymph nodes tend to move and are rubbery. This is part of the bone and rock solid.