I am missing my left pec muscle. Is it not there or is it just underdeveloped? What is the solution?

Hello, Ever since I have lost weight, I realized that there a problem with my left pec muscle. It has always seemed significantly smaller than the right one. I cannot flex it like I can do with the right one. Also, with my left bicep, it is not as strong as the right one and it is more difficult for me to flex it too. Do you think my left pec missing or just underdeveloped? Also, regarding my left bicep, is it underdeveloped too? What is the solution?

Doctor Answers 4

Left pectoral muscle and biceps muscles small or missing

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Thank you for asking about your pectoral and biceps muscles.
  • You probably have what is called Poland's symdrome - and underdevelopment of muscles on the chest, often the arm and sometimes hand maldevelopment as well.
  • The biceps clearly is underdeveloped - because you can use it.
  • The pectoral may be missing.
  • The solution is a custom made chest implant based on a CT scan which is implants on that side of the chest.
  • These work well-
  • Please do not try to save money by having a custom implant by a mouilage (mold) - it will not look as good as it should.
  • Please find a plastic surgeon who does a lot of implants - 
  • Or contact Implantech, a leading implant manufacturer, for a list of plastic surgeons using their implants.
Always see a Board Certified Plastic Surgeon. Best wishes  - Elizabeth Morgan MD PHD FACS

Polands syndrome

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  from your description I gather your issue may be a congenital deformity called "Polands syndrome".  This condition presents asymmetry in the muscle with possible one sided weakness and aesthectically you may see asymmetry usually affecting one side the bodys upper extremities. The sternal head is absent but the clavicular head of the pectoralis major is present. I would recommend in your case either a pectoral implant or possible fat transfer.

Pectoral augmentation

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Losing weight should not have actually reduced the size of your pectoral or biceps muscles. Perhaps they they were not so visible when there was additional fat present. Strength is completely different and may well be a result of less developed muscles.  When a chest muscle is "not there" it is usually quite visible in any event.  This may be a functional, and not only an aesthetic question.  As with anything in medicine, the solution is to diagnose the issue first, and then come up with a treatment that fits the problem.

Joshua Korman, MD
Mountain View Plastic Surgeon
5.0 out of 5 stars 25 reviews

Left Pectoral and Biceps Augmentation

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If this in indeed a difference in the size of the pectoral and biceps muscle, the options would be fat grafting vs pectoral/biceps implants. It all depends on how much difference exists. A small difference would be treated by fat injections...if you have enough fat to harvest. But larger differences are better served by implants.

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