What conditions other than malignancy can present with elevated 1 25D levels?
• Increased production of 1,25D by non-renal tissues has been reported with sarcoidosis, certain infections (tuberculosis, invasive histoplasmosis, etc.), and other granulomatous disorders (granulomatosis with polyangiitis, Crohn disease, giant cell polymyositis, foreign–body granulomas from silicone, paraffin, polymethyl methacrylate, etc.).
• Reduced catabolism of 1,25D (loss of function mutation of the 24-hydroxylase encoding gene, CYP24A1) can present as unexplained hypercalcemia. The adult phenotype includes varying degrees of hypercalcemia, hypercalciuria, nephrolithiasis/nephrocalcinosis, low PTH, higher than expected 1,25D levels, and CKD. Pregnancy associated hypercalcemia in women without prior hypercalcemia or nephrocalcinosis has been reported, and can be complicated by maternal hypertension, acute pancreatitis, and fetal demise.