Description

Calcinosis is a well-documented manifestation seen in up to 40% of patients with juvenile dermatomyositis. It is an uncommon feature in adult-onset dermatomyositis.1 We present a rare occurrence of calcinosis with unusual distribution in a 51-year-old male.

18-months after diagnosis, our patient was seen in clinic following an episode of cellulitis. His muscle weakness and skin rash had responded well to steroid and oral methotrexate therapy. Examination identified a hard, irregular and extensive mass palpable across the abdomen. Laboratory studies revealed normal renal function, with creatine kinase elevated at 440 IU/l. Serum calcium, phosphate, parathyroid hormone and vitamin D were all within normal parameters. Malignancy was considered but the mass did not correspond to a specific abdominal organ. Due to the patient’s body weight of 170 kg ultrasound assessment was limited.

An abdominal CT scan (figure 1) identified extensive calcification in the subcutaneous fat overlying the anterior abdominal wall and buttocks, with normal intra-abdominal viscera.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1

(A,B) CT imaging delineating calcification within the soft tissues of the abdomen, with unremarkable changes in the remaining intra-abdominal viscera.

Despite this development, the patient demonstrated clinical improvement in his muscle power and skin rash. Consequentially, no change in the patient’s management was made.

Calcinosis of the skin and muscle is unusual but recognised findings in adult-onset dermatomyositis, which typically have a predilection for sites of trauma.2 Other causes of ectopic calcification such as hyperparathyroidism, hypervitaminosis D and nephropathy were excluded by relevant investigations.

We demonstrate fascinating images illustrating the development of exclusive subcutaneous fat calcinosis, also known as calcinosis universalis3 4–a phenomenon that is only rarely reported in adult-onset dermatomyositis.