E1281. Acro-Osteolysis Review: The Tip of the Iceberg
  1. Christopher Bailey; JBSA Lackland AFB
  2. Nathan Cecava; JBSA Lackland AFB
  3. Douglas Byerly; JBSA Lackland AFB
  4. David Oettel; JBSA Lackland AFB
  5. Robert Macgregor; JBSA Lackland AFB
  6. Orest Kayder; Detroit Medical Center
  7. Hamed Kordbacheh; Detroit Medical Center
Acro-osteolysis is osseous destruction of the terminal tuft or midshaft of the distal phalanges of the hands and feet. Radiographic recognition of acro-osteolysis is straightforward, but identifying the underlying cause and a need for advanced imaging or tissue diagnosis can be more elusive. The purpose of this project will be to educate the radiologist on types, causes, and associated imaging and clinical findings important in the evaluation of acro-osteolysis.

Educational Goals / Teaching Points
Comprehend the different types and etiologies of acro-osteolysis. Understand basic pathophysiology in various disease processes which lead to erosion of the distal phalanx. Recognize which associated imaging and clinical features will assist the radiologist in formulating an accurate differential diagnosis. Understand when advanced imaging and tissue diagnosis is required in acro-osteolysis.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Understanding distal phalangeal anatomy is key to understanding disease mechanisms of erosion in both terminal tuft and midshaft acro-osteolysis. Radiographs of the hands and feet are the primary means for identifying the presence and distribution of different types of acro-osteolysis. Terminal tuft acro-osteolysis can be caused by a variety of conditions including traumatic and thermal injuries, diabetic neuropathy, vascular disease, infection, inflammatory arthritis, scleroderma, sarcoidosis, and epidermolysis bullosa. Band acro-osteolysis can be seen in sarcoidosis, renal osteodystrophy, Hadju-Cheyney syndrome, or vinyl chloride exposure. Considering the variety of acro-osteolysis causes, secondary imaging modalities can assist in refining differential diagnosis. Chest radiography/CT, extremity CT/MRI, ultrasound, and clinical information should be reviewed to assist in making distinctions between various causes of acro-osteolysis. For example, a chest CT with a patulous esophagus and interstitial lung disease will raise suspicion for scleroderma. In some cases of acro-osteolysis, it may not be possible to distinguish benign and malignant etiologies with the available clinical and radiographic information. The radiologist must be aware of this limitation and understand when further imaging or tissue sampling is appropriate.

Acro-osteolysis should be easily recognized by the radiologist on radiography, but formulating an accurate differential diagnosis is more challenging. Items important in producing a refined differential include recognition of distribution and type of acro-osteolysis, interrogating the pertinent imaging history for associated findings and evaluating the supporting clinical data. In many cases, this will be enough to make an accurate diagnosis. In select cases, the radiologist must recognize when advanced imaging and tissue biopsy are required for diagnosis and disposition to avoid unnecessary patient morbidity.