Unicameral (Simple) Bone Cyst Clinical Presentation

Updated: May 12, 2023
  • Author: Charles T Mehlman, DO, MPH; Chief Editor: Harris Gellman, MD  more...
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History and Physical Examination

Most patients with a unicameral (simple) bone cyst (UBC) present to the orthopedic surgeon after sustaining a pathologic fracture. Such fractures most commonly involve either the proximal humerus or the proximal femur. The events leading up to the fracture may range from fairly trivial (eg, throwing a ball) to more substantial (eg, a hard fall while playing soccer). As with all patients who have sustained a fracture, a careful physical examination of the patient should include efforts to exclude the possibility of an open fracture and a neurocirculatory insult.

In other instances, patients may present to emergency department physicians, their primary care physicians, or orthopedic surgeons for other reasons, and radiographs obtained in the workup of other complaints may identify asymptomatic UBCs. Such incidental diagnosis of a "bone tumor" may be quite disconcerting to the child's parents and family. Random bone tumor discussions with such a child's family are contraindicated. Medical personnel who eagerly deliver well-intentioned but inaccurate discussions of bone tumors often needlessly terrify families.

In either scenario, a review of the patient's past history, as well as their family's past history relative to fractures, rheumatologic conditions, bone tumors, endocrine disease, and cancer, is appropriate. Physical examination of the patient should also include a screening examination of the axial skeleton and the uninvolved extremities. Any other identified abnormalities may require further plain radiographs. [42]  Palpation of major lymph node areas (eg, the axillary and inguinal fields) is also appropriate; infection and malignancy are part of the differential diagnosis.