Severe Acro-osteolysis Mimicking Arthritis Mutilans in a Patient with Primary Hyperparathyroidism: A Case Report

Background: Primary hyperparathyroidism (PHPT) should be considered in the differential diagnosis of a patient with suspected secondary osteoporosis, and severe osteoporosis with multiple fractures is frequently the first clinical manifestation of the disease. Case Presentation: Mutilating arthritis (arthritis mutilans) can be part of the clinical presentation of a number of rheumatic diseases, most commonly seen in psoriatic arthritis, rheumatoid arthritis, and juvenile idiopathic arthritis, but also in systemic lupus, systemic sclerosis, and multicentric reticulohistiocytosis. Evidence exists that subperiosteal and subchondral bone resorption, seen in PHPT, could induce the so-called ‘osteogenic synovitis’, which could eventually lead to the development of a secondary osteoarthritis with bone deformities. Conclusion: Here, we present a case report of a patient initially diagnosed with PHPT who presented with mutilating arthritis of the finger joints and discuss whether the severe acro-osteolysis is a manifestation of the endocrinopathy or whether there is a co-existing undiagnosed inflammatory joint disease.