Why is Poland Syndrome a “syndrome” and not a rare disease? Well syndrome is taken from the Greek word “sundromē”, made up of two words sun- ‘together’ + dramein ‘to run’, literally speaking “together-run”. Poland syndrome is a group of identifiable symptoms without a known cause. Yes, there are theories as to why Poland syndrome occurs, it is known to happen during fetal development but exactly what causes the characterised symptoms in unknown.
A disease on the other hand has a known cause. A syndrome can constitute a number of diseases behind it. For example metabolic syndrome which may have a combination of diseases beneath like heart disease and diabetes.
Poland syndrome typically like other syndromes doesn’t always have exactly the same combination of symptoms either. Some people have webbed fingers, some just have a smaller hand, some have missing parts of chest muscles whilst for others it can be completely absent.
Diseases also cause changes in anatomy where as syndromes may not. In the case of Poland Syndrome, it is not something that develops overtime you either have it or you don’t. You can’t develop it later in life, although you might not realise you have Poland Syndrome until adulthood you were born with it.
So in summary a syndrome is a collection of symptoms, a disease on the other hand is an abnormal condition of a body system or organ. A syndrome can be a collection of diseases. That’s why Poland syndrome is a syndrome and not a disease.