CASE 16448 Published on 13.09.2019

Tumoral calcinosis of the sternum and hip: a rare cause of an antalgic gait and a bony prominence in a patient with chronic renal failure

Section

Musculoskeletal system

Case Type

Clinical Cases

Authors

Shakeel Faruqui1, Faraz Hosseini-Ardehali2, Bertrand Annan1, Babak Langroudi1

1 East and North Hertfordshire NHS Trust, Stevenage, Hertfordshire, UNITED KINGDOM
2 MBBS, Royal Free London NHS Trust

Patient

54 years, male

Categories
Area of Interest Musculoskeletal soft tissue ; Imaging Technique CT, Nuclear medicine conventional
Clinical History

A 54-year-old man with chronic renal failure was admitted to a district general hospital with a three week history of left hip pain and reduced mobility of the joint. He had also noticed a bony lump growing over the sternal notch over the course of several months.

Imaging Findings

1) Plain radiograph pelvis: Revealed a large (10cm x 6.5cm) area of calcification adjacent to the left greater trochanter [Fig. A].
2) CT Pelvis: Demonstrates peri-articular multilobulated calcification anterolateral to the left greater trochanter. Multiple fluid calcium levels, demonstrating the sedimentation sign may be seen [Fig. B].
3) CT Thorax:  Revealed a 3cm x 3cm calcification adjacent to the sternum. [Fig. C].
4) Nuclear medicine scan:  demonstrated a focus of retained radiotracer in the region of the lower pole of right lobe of the thyroid gland suggestive of a parathyroid adenoma. [Fig. D].

Discussion

Background:
Secondary tumoral calcinosis involves extensive calcification of periarticular tissues and is often associated with chronic renal failure, presenting as a palpable cutaneous mass that is usually found in the extensor aspects of the periarticular regions of hips, knees, elbows, shoulder, and more rarely the feet, hands and spine. [1, 2, 3] This is most frequently attributed to hyperparathyroidism and disturbances of calcium-phosphate metabolism. [2]
Primary tumoral calcinosis is a radiologically and histologically indistinguishable condition seen in patients without chronic renal failure, affecting a younger subgroup of patients, and is a hereditary condition [3]. In this condition, biochemical tests of calcium-phosphate metabolism and parathyroid hormones are often normal [4]
Clinical Perspective:
A 54-year-old male patient was admitted with a three week history of left-sided hip pain, which resulted in reduced mobility and the patient had an antalgic gait. In addition, he described hard prominence over the sternal notch. He had a coronary artery bypass procedure a year back. There was no known history of trauma to either the hip or the sternum. The sternal mass was recently biopsied at another hospital , having produced a few millilitres of a creamy aspirate.

Imaging Perspective:
Plain radiography of hip demonstrated a large area of calcification. Subsequent CT Pelvis demonstrated periarticular multilobulated calcification anterolateral to the greater trochanter. A previous CT Chest was reviewed and calcification was noted juxtaposed to the sternum (X-ray Chest was not available). The case was discussed in the multidisciplinary team meeting and as the Chest CT did not show any parathyroid mass. A nuclear medicine scan was performed which demonstrated a focus of retained radiotracer in the region of the lower pole of the right lobe of the thyroid gland suggestive of a parathyroid adenoma.

Outcome:
The patient subsequently underwent a total parathyroidectomy. An Ultrasound-guided steroidal injection into the left trochanteric region  was performed and subsequent CT demonstrated complete resolution of calcification. The blood calcium levels also improved.

Teaching points:
•    Soft-tissue calcification should be considered as a cause of joint pain or bony prominence in patients with renal failure together with a broad range of differential diagnoses that have similar radiological appearances. [5, 6, 7]  
•    Tumoral calcinosis is a rare condition present in only 0.5% - 1.2% of patients with renal failure and therefore may be misdiagnosed. [5]
•    It is important to correlate radiological appearances with biochemical findings in patients who are known to have conditions causing metabolic abnormalities.

Written informed patient consent for the publication has been obtained.

Differential Diagnosis List
Calcinosis-circumscripta: Soft tissue calcification associated with connective tissue disease e.g. dermatomyositis
Hydroxyapatite deposition disease (HADD): Deposition of hydroxyapatite crystals in tendons/bursae
Myositis ossificans: Heterotopic ossification within muscle, following haemorrhage or trauma
Secondary tumoral calcinosis involving left hip and sternum
Parosteal osteosarcoma: Subtype of osteosarcoma presenting radiographically as a lobulated mass
Final Diagnosis
Secondary tumoral calcinosis involving left hip and sternum
Case information
URL: https://www.eurorad.org/case/16448
ISSN: 1563-4086