Post-traumatic cystic bone lesion
Updates to Article Attributes
Post-traumatic cystic bone lesions, also known as fracture cysts or transient fatty cortical defects,are benign, transient post-fracture cysts, which are relatively uncommon and usually appear about one-to-two months after traumatic fracture.
Epidemiology
They are rare but may be under recognised-recognised, as monitoring after fracture often is only clinicallyclinical. They have most often been reported in children of growing age. The most common reported site is the distal radius 1-3.
Clinical presentation
Though mostly asymptomatic in nature, patients with these transient lesions can present with moderate soft swelling 1.
Pathology
Characteristics of these lesions are:
- non-expansile cyst of <1 cm in diameter
- may be multiple
- close proximity to former fracture site
- may contain fat
Typically encountered at about a month after initial fracture, they have been reported to occur as late as 18 months after the initial trauma 1.
Aetiology
There is ongoing debate whether these transient lesions represent intramedullary fat inclusions cysts (most accepted theory) or resorption cysts of excessive periosteal reaction caused by subperiosteal hematoma or intraosseous haemorrhage 1,3.
Radiographic appearance
Plain radiograph
Typical appearances are that of a subcentimeter oval or round lucency without expansivity, peripheral condensation or periosteal reaction and close proximity to the site of former fracture.
CT
They can sometimes show well-defined intracortical fatty density 6,7.
MRI
May show fatty signal, with signal loss on fat suppressed sequences1.
Treatment and prognosis
As all hitherto reported lesions resolved spontaneously, no treatment is needed.
Differential diagnosis
Encountering a cyst-like lesion close to a healing fracture (probably even greenstick fracture) can make the diagnosis straightforward. More challenging diagnostic scenarios, however, can comprise lack of former studies (or unawareness of their existence, unavailability at other institutions, etc), incomplete clinical information or a long period between initial fracture and lesion on actual imaging studies.
In those cases and in general differential diagnostic considerations may include:
- unicameral bone cyst: usually expansile
- non-ossifying fibroma (fibroxanthoma): larger
- transient cyst-like/fatty cortical lesions
- osteomyelitis: usually symptomatic, abnormal blood samples
-<p><strong>Post-traumatic cystic bone lesions</strong>, also known as<strong> fracture cysts</strong>,<strong> </strong>are benign, transient post-fracture cysts, which are relatively uncommon and usually appear about one-to-two months after traumatic fracture.</p><h4>Epidemiology</h4><p>They are rare but may be under recognised, as monitoring after fracture often is only clinically. They have most often been reported in children of growing age. The most common reported site is the distal <a href="/articles/radius">radius</a> <sup>1-3</sup>.</p><h4>Clinical presentation</h4><p>Though mostly asymptomatic in nature, patients with these transient lesions can present with moderate soft swelling <sup>1</sup>.</p><h4>Pathology</h4><p>Characteristics of these lesions are:</p><ul>- +<p><strong>Post-traumatic cystic bone lesions</strong>, also known as<strong> fracture cysts</strong> or <strong>transient fatty cortical defects</strong>,<strong> </strong>are benign, transient post-fracture cysts, which are relatively uncommon and usually appear about one-to-two months after traumatic fracture.</p><h4>Epidemiology</h4><p>They are rare but may be under-recognised, as monitoring after fracture often is only clinical. They have most often been reported in children of growing age. The most common reported site is the distal <a href="/articles/radius">radius</a> <sup>1-3</sup>.</p><h4>Clinical presentation</h4><p>Though mostly asymptomatic in nature, patients with these transient lesions can present with moderate soft swelling <sup>1</sup>.</p><h4>Pathology</h4><p>Characteristics of these lesions are:</p><ul>
-</ul><p>Typically encountered at about a month after initial fracture, they have been reported to occur as late as 18 months after the initial trauma <sup>1</sup>.</p><h5>Aetiology</h5><p>There is ongoing debate whether these transient lesions represent intramedullary fat inclusions cysts (most accepted theory) or resorption cysts of excessive periosteal reaction caused by subperiosteal hematoma or intraosseous haemorrhage <sup>1,3</sup>.</p><h4>Radiographic appearance</h4><h5>Plain radiograph</h5><p>Typical appearances are that of a subcentimeter oval or round lucency without expansivity, peripheral condensation or periosteal reaction and close proximity to the site of former fracture.</p><h4>Treatment and prognosis</h4><p>As all hitherto reported lesions resolved spontaneously, no treatment is needed.</p><h4>Differential diagnosis</h4><p>Encountering a cyst-like lesion close to a <a href="/articles/fracture-healing">healing fracture</a> (probably even <a href="/articles/greenstick-fracture">greenstick fracture</a>) can make the diagnosis straightforward. More challenging diagnostic scenarios, however, can comprise lack of former studies (or unawareness of their existence, unavailability at other institutions, etc), incomplete clinical information or a long period between initial fracture and lesion on actual imaging studies.</p><p>In those cases and in general differential diagnostic considerations may include:</p><ul>- +<li>may contain fat</li>
- +</ul><p>Typically encountered at about a month after initial fracture, they have been reported to occur as late as 18 months after the initial trauma <sup>1</sup>.</p><h5>Aetiology</h5><p>There is ongoing debate whether these transient lesions represent intramedullary fat inclusions cysts (most accepted theory) or resorption cysts of excessive periosteal reaction caused by subperiosteal hematoma or intraosseous haemorrhage <sup>1,3</sup>.</p><h4>Radiographic appearance</h4><h5>Plain radiograph</h5><p>Typical appearances are that of a subcentimeter oval or round lucency without expansivity, peripheral condensation or periosteal reaction and close proximity to the site of former fracture.</p><h5>CT</h5><p>They can sometimes show well-defined intracortical fatty density <sup>6,7</sup>.</p><h5>MRI</h5><p>May show fatty signal, with signal loss on <a title="Fat suppressed imaging" href="/articles/fat-suppressed-imaging">fat suppressed sequences</a> <sup>1</sup>.</p><h4>Treatment and prognosis</h4><p>As all hitherto reported lesions resolved spontaneously, no treatment is needed.</p><h4>Differential diagnosis</h4><p>Encountering a cyst-like lesion close to a <a href="/articles/fracture-healing">healing fracture</a> (probably even <a href="/articles/greenstick-fracture">greenstick fracture</a>) can make the diagnosis straightforward. More challenging diagnostic scenarios, however, can comprise lack of former studies (or unawareness of their existence, unavailability at other institutions, etc), incomplete clinical information or a long period between initial fracture and lesion on actual imaging studies.</p><p>In those cases and in general differential diagnostic considerations may include:</p><ul>
-<li>transient cyst-like cortical lesions</li>- +<li>transient cyst-like/fatty cortical lesions</li>
References changed:
- 6. Malghem J, Malghem MB, Malghem. Transient fatty cortical defects following fractures in children. (1986) Skeletal radiology. <a href="https://doi.org/10.1007/BF00348864">doi:10.1007/BF00348864</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/3738540">Pubmed</a> <span class="ref_v4"></span>
- 7. Malghem J, Malghem MB, Malghem CD, Malghem CP, Malghem. Transient cyst-like cortical defects following fractures in children. Medullary fat within the subperiosteal haematoma. (1990) The Journal of bone and joint surgery. British volume. <a href="https://doi.org/10.1302/0301-620X.72B5.2211773">doi:10.1302/0301-620X.72B5.2211773</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/2211773">Pubmed</a> <span class="ref_v4"></span>
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