FDG-PET detects extensive calcinosis cutis in anti-NXP2 antibody-positive dermatomyositis

A 65-year-old woman presented with mild proximal muscle weakness, polyarthralgia, erythema on the face, Gottron’s papules, and subcutaneous indurations (Fig. 1A) that were spreading throughout her body, especially to the buttocks and extremities, over the course of 1 year. Biochemical analysis revealed normal creatine kinase levels with mild increment in aldolase. Anti-NXP-2 antibodies were detected. Muscle biopsy from the left biceps brachii revealed lymphocyte infiltration and perifascicular atrophy. Skin biopsy from erythema on the face showed liquefaction degeneration and that from subcutaneous induration on the left upper arm showed calcinosis and inflammatory cell invasion in the dermis and panniculitis. She was diagnosed...