Differential response of idiopathic sporadic tumoral calcinosis to bisphosphonates

Abstract

Context: Tumoral calcinosis is a disorder of phosphate metabolism characterized by ectopic calcification around major joints. Surgery is the current treatment of choice, but a suboptimal choice in recurrent and multicentric lesions.

Aims: To evaluate the efficacy of bisphosphonates for the management of tumoral calcinosis on optimized medical treatment.

Settings and design: The study was done in the endocrine department of a tertiary care hospital in South India. We prospectively studied two patients with recurrent tumoral calcinosis who had failed therapy with phosphate lowering measures.

Materials and methods: After informed consent, we treated both patients with standard age adjusted doses of bisphosphonates for 18 months. The response was assessed by X ray and whole body 99mTc-methylene diphosphonate bone scan at the beginning of therapy and at the end of 1 year. We also estimated serum phosphate levels and urinary phosphate to document serial changes.

Results: Two patients (aged 19 and 5 years) with recurrent idiopathic hyperphosphatemic tumoral calcinosis, following surgery were studied. Both patients had failed therapy with conventional medical management - low phosphate diet and phosphate binders. They had restriction of joint mobility. Both were given standard doses of oral alendronate and parenteral pamidronate respectively for more than a year, along with phosphate lowering measures. At the end of 1 year, one of the patients had more than 95% and 90% reduction in the size of the lesions in right and left shoulder joints respectively with total improvement in range of motion. In contrast, the other patient (5-year-old) had shown no improvement, despite continuing to maintain normophosphatemia following treatment.

Conclusions: Bisphosphonate therapy in tumoral calcinosis is associated with lesion resolution and may be used as a viable alternative to surgery, especially in cases with multicentric recurrence or treatment failure to other drugs.

Keywords: Bisphosphonates; fibroblast growth factor 23; hyperphosphatemia; tumoral calcinosis.

Figure 1

99mTc-methylene diphosphonate whole body bone scan (a and b with anterior and posterior views) and their respective single-photon emission computed tomography (SPECT). Computed tomography (CT) fused (c and d) images before and after treatment. a and c are pre treatment images shows intense uptake in bilateral shoulder joints with evidence of shoulder joints infiltration on SPECT. CT fused images. b and d are posttreatment images showing significant reduction of activity from both shoulder joints

Figure 2

99mTc- methylene diphosphonate whole body bone scan (a and b with anterior and posterior views) and their respective single-photon emission computed tomography (SPECT). Computed tomography (CT) fused (c and d) images before and after treatment. a and c are pretreatment images shows intense uptake in right gluteal with large calcified soft tissue mass on SPECT. CT. b and d are posttreatment images showing significant increase in size of calcified soft tissue mass with increased tracer uptake in right gluteal region