Idiopathic calcinosis cutis causing cubital tunnel syndrome: A case report and review of literature

Calcinosis cutis is a type of heterotopic calcification where abnormal calcium deposition occurs in skin or subcutaneous tissue. Among the subtypes of calcinosis cutis, the idiopathic variety occurs without underlying biochemical calcium abnormality. We report a rare case of idiopathic calcinosis cutis causing cubital tunnel syndrome. A 63-year-old female presented with pain and numbness in the ulnar aspect of her left hand. The X-ray of the left elbow showed deposition of radiopaque material on the posteromedial aspect. Her nerve conduction study showed evidence of ulnar nerve compression at the elbow supporting the diagnosis of ulnar nerve compression by the mass of calcium deposition. Surgical exploration was performed, and significant ulnar nerve compression was noted due to the mass effect of the calcium deposition. Excision of the mass and ulnar nerve decompression with anterior transposition was performed with satisfactory outcomes. Although calcinosis cutis causing cubital tunnel syndrome has been previously reported, all patients had some form of calcium dysregulation. We report the first case of ulnar nerve compression at the cubital tunnel due to idiopathic calcinosis cutis. Excision of the mass and ulnar nerve decompression with anterior transposition was successful in our patient despite the incomplete excision of the calcium deposition.