This is a term many medical transcriptionists seem to struggle with.
"Shoddy" is defined as something that is cheap and tawdry. Keeping this in mind, it makes sense that there is no such thing as a "tawdry lymphadenopathy."
"Shotty" is meant as being like buckshot, which is scattered and lumpy when it hits a target; i.e., shotty lymphadenopathy is lymph nodes that are scattered and lumpy.
The correct term is always shotty lymphadenopathy.