Published online Aug 6, 2019. doi: 10.12998/wjcc.v7.i15.2081
Peer-review started: February 11, 2019
First decision: May 31, 2019
Revised: June 4, 2019
Accepted: June 20, 2019
Article in press: June 21, 2019
Published online: August 6, 2019
Oncogenic osteomalacia caused by phosphaturic mesenchymal tumors is very difficult to detect. We report a case of tumor-induced osteomalacia caused by a phosphaturic mesenchymal tumor of the left femur in a middle-aged woman after medical imaging and biopsy.
A 57-year-old woman presented with progressive bone pain for five years. She was diagnosed with hypophosphatemic osteomalacia, as her laboratory data showed low serum phosphorus and low serum calcium. Her knee joint radiography revealed an osteolytic lesion of the left femur. A computed tomography scan showed mixed density shadows in the left femur. Magnetic resonance imaging of the left femur showed the presence of an oval area with a hypointense signal in T1-weighted magnetic resonance imaging (MRI) and high-low mixed signal in T2-weighted MRI. Biopsy samples revealed the presence of short spindle cells, vascularization, and characteristics of phosphaturic mesenchymal tumors. Tumor resection was performed, and the clinical presentations and laboratory abnormalities were reversed.
Diagnosis of oncogenic osteomalacia is difficult due to the varieties and localization of source tumors and absence of pathognomonic biomedical signs. Our case highlights the importance of a combination of medical imaging and biopsy in the diagnosis of oncogenic osteomalacia caused by a phosphaturic mesenchymal tumor.
Core tip: Oncogenic osteomalacia caused by phosphaturic mesenchymal tumors is not easily identifiable or detectable due to its rarity and nonspecific presentations. Herein, we provide a successful example of diagnosis of phopshaturic mesenchymal tumor-induced oncogenic osteomalacia in a female patient who presented progressive bone pain. Our case emphasizes that histologically benign phosphaturic mesenchymal tumors that are responsible for oncogenic osteomalacia can also cause bone destruction.