--three forms: primary (tumor), secondary (renal dz), and tertiary (renal dialysis)
--F>M, 3:1
--30-50 years of age
--S/Sx: weakness, lethargy, polydipsia, polyuria, elevated alk phos and parathormone levels
--X-ray: osteopenia, accentuated trabeculae, subperiosteal resorption (in hand, hallmark feature)
--HANDS: subperiosteal resorption, radial margins of proximal and middle phalanges of 2nd and 3rd digits show acroosteolysis (scooping)
--"tuft" resorption of fingertips, DDX: SLE, PVC exposure, scleroderma
--brown tumors (hemorrhagic giant cell proliferations, usu in finger, femoral head, tibia, rib)
--more bone changes: SI mb resorbed, distal clavicles, pubis, lamina dura around teeth, "salt and pepper" skull
--spine osteopenic, trabeculae accentuated, end plates concave, "rugger jersey" spine, bold horizontal stripes
--Soft tissue changes include: nephrocalcinosis, renal calculi, chondrocalinosis, calcification in various periarticular tissues and visceral organs, this is nephrocalcinosis: