Pseudocyst of the humerus

Last revised by Mohammad Taghi Niknejad on 10 Jan 2022

Pseudocyst of the humerus also referred as a humeral head pseudolesion, is a normal anatomical variant due to increased cancellous bone in the region of the greater tuberosity of the humerus which is seen as a lucent lesion on radiography.

Hyperemia and disuse caused by shoulder problems (such as rotator cuff disorders) cause this area of lucency to appear more lucent and mimic a lytic lesion (e.g. chondroblastoma, infection, or even a metastatic focus) and mistakenly undergo biopsy.

Therefore, pseudocyst of the humerus is one of the skeletal "do not touch" lesions.

Radiographic features

Plain radiograph

May show a lucent lesion in the region of the humeral greater tuberosity, often with a somewhat well defined inferior curvilinear margin whilst the upper margin is generally ill-defined 2. Pseudocysts are thought to be so radiographically characteristic that they should not be biopsied.

CT

Similar appearances to those on plain radiograph.

Nuclear medicine - bone scan

Bone scan may show increased radionuclide uptake due to hyperemia (and thus convince the surgeon to perform a biopsy).

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