Malignant phosphaturic mesenchymal tumor with pulmonary metastasis: A case report

Medicine (Baltimore). 2017 Apr;96(17):e6750. doi: 10.1097/MD.0000000000006750.


Rationale: Phosphaturic mesenchymal tumor (PMT) is a new tumor entity of soft tissue and bone tumor recently accepted by the World Health Organization, which typically causes the paraneoplastic syndrome of tumor-induced osteomalacia (TIO). The majority of PMTs follow a benign clinical course and local recurrence occurs in < 10% of cases, malignant PMTs with distant organ metastasis are extremely uncommon.

Patient concerns: We reported a 41-year-old woman who was diagnosed with PMT 10 years ago with a repeated recurrence and pulmonary metastasis.

Diagnoses: Based on clinical manifestations, MRI scan, serum biochemical indicators evaluation, followed by histopathological examination, the patient was diagnosed as malignant PMT with pulmonary metastasis.

Interventions: The patient was treated with calcium, phosphorus, and vitamin D after surgical resection and measured the serum ion concentrations every 3 months.

Outcomes: The patient had a favorable outcome for 10 months without recurrence.

Lessons: PMTs lack of characteristic histological morphology, some recurrence cases may appear benign morphologically; the malignant PMTs are easily overlooked. Patients with PMT should be carefully evaluated and monitored, in order to early identify its malignant potential.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Bone Neoplasms / diagnosis
  • Bone Neoplasms / pathology*
  • Bone Neoplasms / therapy
  • Diagnosis, Differential
  • Female
  • Humans
  • Hypophosphatemia / etiology
  • Liver Neoplasms / diagnosis*
  • Liver Neoplasms / pathology
  • Liver Neoplasms / secondary
  • Lung Neoplasms / diagnosis
  • Lung Neoplasms / secondary*
  • Lung Neoplasms / therapy
  • Mesenchymoma / diagnosis*
  • Mesenchymoma / pathology
  • Mesenchymoma / secondary
  • Neoplasms, Connective Tissue / diagnosis
  • Neoplasms, Connective Tissue / pathology*
  • Neoplasms, Connective Tissue / therapy
  • Osteomalacia / etiology
  • Paraneoplastic Syndromes / diagnosis
  • Paraneoplastic Syndromes / pathology

Supplementary concepts

  • Malignant mesenchymal tumor