Shoulder pain is a common presenting symptom and may be secondary to a variety of underlying causes. We report a case of shoulder pain caused by a periarticular neurofibroma. Although neurofibromatosis has many classic musculoskeletal manifestations1, to our knowledge it has not been reported within the shoulder girdle. The patient was informed that data concerning the case would be submitted for publication, and she consented. A thirty-eight-year-old woman presented with a two-year history of atraumatic pain in the left shoulder. The pain was insidious in onset, diffuse and dull, nonradiating, and nonprogressive. The patient reported that she did not have pain at rest but experienced pain with any activity and at night, particularly when lying on her left side. She otherwise felt well. Constitutional symptoms were absent, as were proximal pain or neurological symptoms. She had anteromedial elbow pain but no symptoms in any other joint. The patient was diagnosed with neurofibromatosis-1 at eight months of age. Neurofibromatosis is one of the most common autosomal dominant inherited diseases. Although it classically affects neural tissue, because of its ubiquitous nature it can manifest within bone and soft tissue. This patient initially presented with a congenital pseudarthrosis of the tibia, which ultimately required surgery. She took no medications, had no allergies, was a nonsmoker, and worked as a cashier at a grocery store. The patient's mother and maternal aunt, a male sibling, and two of the patient's four children had neurofibromatosis-1. Clinical examination revealed a healthy-appearing woman. Her height and weight were within the normal range. Examination of the integument revealed multiple cutaneous neurofibromas and axillary freckling. Atrophy of the left supraspinatus and infraspinatus was noted, while the deltoid contour was well preserved bilaterally. No palpable mass or tenderness was noted around the proximal part of the humerus, with the …