Tumor-induced phosphopenic osteomalacia: modern approaches to diagnostics and treatment

Phosphopenic osteomalacia (PPOM) is a rare variant of paraneoplastic syndrome caused by tumor synthesis of fibroblast growth factor 23 (FGF23). FGF23 secretion leads to a decrease in phosphate reabsorption and calcitriol levels, which leads to the development of severe hypophosphataemia and hypocalcaemia. FGF23 synthesis is predominantly associated with benign mesenchymal tumors, but has also been described in malignant neoplasms. The main clinical manifestations of PPOM are generalized myalgias and myopathy, ostealgia, pathological fractures, etc. The diagnosis of the disease requires a step-by-step investigation using somatostatin receptor-based imaging techniques, as these have the highest sensitivity for the detection of neoplasms causing osteomalacia. Surgical intervention is clearly the treatment of choice. Promising non-surgical methods include treatment with burosumab and somatostatin analogues.