If Aviva's doctor finds, through an ultrasound, an abnormal growth of tissue outside the uterus, then Aviva is most likely to be suffering from a tumor.
A tumor is a mass of cancerous cells that divide in an uncontrolled manner, which is due to the lack of a suitable cellular mechanisms that stop the growth in specific stages of the cell cycle such as the S stop point before DNA replication.
Therefore, with this data, we can see that tumors generate a mass of cells that may constraint adjacent organs and cause pain.
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