Hi Tony,
From these pictures it almost looks it may be 2 embryos that were encapsulated in one seed coat (fraternal twins). Then the stems fused as it grew, looks like you can see a separation line along the stem.
If the freak grows enough to throw some lateral branches you might want to take some clones. Quite interesting. These kinds of things drive me crazy because they are so unusual and you get so intrigued…without knowing what the outcome will be.