A hematoma may result from all of the following, EXCEPT?

A hematoma is a localized collection of blood outside of blood vessels, typically occurring as a result of injury or trauma to blood vessels during a medical procedure such as venipuncture. The correct answer indicates that the failure of the needle to enter the vein does not directly lead to the formation of a hematoma.

When a needle fails to enter a vein, it does not create the conditions necessary for a hematoma. In that case, there might be no puncture made, so there is little to no bleeding that can accumulate and form a hematoma. The other scenarios, such as removing the needle while a tourniquet is still tied, not applying adequate pressure post-procedure, and excessive probing, can all contribute to the tearing of blood vessels or allow blood to leak into surrounding tissues, resulting in a hematoma.

Understanding how these various factors contribute to or prevent the formation of hematomas is crucial for safe venipuncture and patient care in medical laboratory practice.