focusrite rednet r1 Oncogenic osteomalacia is caused by a small mesenchymal tumour characterised by phosphaturia, hypophosphatemia, decreased serum vitamin D3 level, and osteomalacia.Phosphaturic mesenchymal tumour of the mixed connective tissue type (PMTMCT) is the commonest subtype and usually involves a s??dett?v? kakkurengas single site.We report a case of PMTMCT involving the left proximal and shaft of the tibia in a 42-year-old man.