The missed thorn.

Following surgical exploration, a swelling on the back of a boy's hand was thought to be a tuberculous granuloma and was treated as such. Eleven months later, when the lump was re-explored, a plant thorn was retrieved from the middle of a foreign body granuloma. Even though a definite history of trauma is not given, an organic foreign body lesion should be considered in the differential diagnosis of a lytic lesion of bone.