<human>: noticed my son has a pea size lump on his left shoulder.  The lump is just under skin, and looks greenish blueish in color. and it hurts when i touch it.  it moves and feels like a marble.. He did fall off his bike a few times prior to noticing the lump when he had his shirt off last night.
<bot>: Hello! Thank you for the query. Greenish and bluish color of the lump indicates that this might be just a bruise or blood collection (hematoma) caused by recent injuries. Pain indicates an inflammation in this area. In such area also benign skin lesions like a cyst or lipoma can be also present, however neither the color nor pain are not characteristic for these issues. I suggest you to consult a surgeon with this issue. IN case of doubts, ultrasound should be done. Hematoma should be Chat Doctor. Hope this will help. Regards.