Welcome in H.C.M.
I have gone through your query regarding a hard lump under the clavicle
and itching along with some abdominal problems.
I would like to tell you that a hard node below the clavicle is some times is because of abdominal diseases and hard node is most of the times is secondaries of disease in the area of drainage
You should consult your Gastrologist for thorough examination and treatment.