Resolution of Severe Oncogenic Hypophosphatemic Osteomalacia after Resection of a Deeply Located Soft-Tissue Tumour

A. R. M. Radaideh,M. M. Abu-Kalaf,D. Jaradat,M. K. Nusier

doi:10.3747/co.v16i5.412

A. R. M. Radaideh, M. M. Abu-Kalaf + Show 2 more

Open Access

https://doi.org/10.3747/co.v16i5.412

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Journal: Current Oncology	Publication Date: Sep 1, 2009
Citations: 13	License type: CC BY 4.0

Affiliation: University of Jordan, Ministry of Health

Abstract

Oncogenic osteomalacia is a rare metabolic bone disease characterized by phosphate leakage from the kidney and subsequent hypophosphatemia. It is caused by a phosphaturic factor produced by certain tumours. Removal of such tumours can completely cure the condition. Here, we report the case of a patient who was crippled with oncogenic osteomalacia. Extensive study revealed a tumour deeply located in the pelvis; removal of the tumour resulted in complete recovery. The tumour was identified as a mesenchymal tumour (mixed connective-tissue variant). The diagnostic evaluation, differential diagnosis, and treatment are discussed.

Highlights

Tumour-induced osteomalacia 1, known as oncogenic osteomalacia 2, is an acquired disorder that results in markedly deranged mineral and skeletal metabolism
The disorder is characterized by hypophosphatemia, osteomalacia, bone pain, proximal muscle weakness, fractures, and functional disability 3
The patient was treated symptomatically with painkillers. He complained of diffuse bone pain, accompanied by generalized muscle weakness, which led to severe debilitation

Summary

INTRODUCTION

Tumour-induced osteomalacia 1, known as oncogenic osteomalacia 2, is an acquired disorder that results in markedly deranged mineral and skeletal metabolism. A reduction in circulating 1,25(OH)2-vitamin D despite hypophosphatemia is the biochemical hallmark of the disease 4,5. In this disorder, osteomalacia mimics the clinical phenotype of either X-linked (xlhr) or autosomal-dominant hereditary hypophosphatemic rickets (adhr) 5–8. Oncogenic osteomalacia is commonly associated with small, slow-growing tumours of mesenchymal origin that may be difficult to detect 4,5,9. Normalization of serum phosphate and remission of the bone disease can be achieved if the causative tumour is located and completely removed 3,5. We report a case of oncogenic osteomalacia in a 39-year-old man with a mesenchymal tumour in the pelvis. Removal of the tumour resulted in reversal of all the biochemical abnormalities and disappearance of the clinical manifestations

CASE REPORT

DISCUSSION

Findings

CONCLUSIONS