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Lipoma

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Lipomas are benign tumours composed of mature adipocytes. They are the most common soft tissue tumour, seen in ~2% of the population.

Epidemiology

Patients typically present in adulthood (5^th-7^th decades).

Associations

In some cases, multiple lipomas are associated with syndromes and other diseases, including:

Diagnosis

Diagnostic criteria according to the WHO classification of soft tissue and bone tumours (5th edition) ¹⁰:

essential: yellow-tan circumscribed mass; uniform proliferation of mature adipose tissue with atypical hyperchromatic stromal cells
desirable: absence of giant marker/ring chromosomes / MDM2 amplification

Clinical presentation

Typically lipomas are subcutaneous in location and present in adulthood as a soft painless mass in the trunk or proximal extremities. They are likely to have been present for many years and may change size with weight fluctuation.

Pathology

The aetiology of lipomas is unknown ¹⁰. In 5-15% of patients, lipomas are multiple, and ~33% of these will be familial ⁵.

Macroscopic appearance

Benign lipomas are circumscribed soft masses, usually encapsulated, and composed almost entirely of fat. ASuperficial lipomas are usually <5 cm whereas deep lipomas can be >20 cm ¹⁰. A small amount of non-adipose components are often present, representing fibrous septa, areas of fat necrosis, blood vessels, and interposed muscle fibres. Any non-adipose components must be carefully assessed to exclude a more aggressive component. ~~Histology~~ Lipomas containing metaplastic cartilage or bone are called chondrolipomas or osteolipomas respectively ¹⁰.

Microscopic appearance

Histology demonstrates mature adipocytes with no cellular atypia or pleomorphism ⁴.

A minority of lipomas are found in deeper locations and include intramuscular, intermuscular, intrathoracic, and retroperitoneal lipomas. These deep lipomatous masses should be assessed carefully, as they are more likely to be malignant. In fact, lesions in retroperitoneal location should be considered a well-differentiated liposarcoma until proven otherwise ⁵.

Intramuscular lipomas have nearly identical histology to superficial lipomas; however, intramuscular lesions tend to invade the adjacent musculature and commonly lack a capsule. ~~Thus, these~~These are sometimes known as infiltrating ~~lipoma~~lipomas. In contradistinction, intermuscular lipomas do not exhibit local invasion and tend to be lobular or dumbbell-shaped, easily separated from adjacent soft tissues during surgical resection ^6,7.

Location

~~In 5-15% of patients,~~Most lipomas are ~~multiple~~superficial in the subcutaneous tissues ¹⁰. A minority of lipomas are found in deeper locations and include intramuscular, intermuscular, intrathoracic, and ~~approximately a third of these will be familial~~ ⁵retroperitoneal lipomas.

~~Location~~

central nervous system and spine
head and neck
- parotid lipoma
thoracic
abdominopelvic
urogenital
- peritesticular lipoma
- spermatic cord lipoma
musculoskeletal
- intraosseous lipoma
- intramuscular lipoma
- intermuscular lipoma
- intra-articular lipoma
- parosteal lipoma
- subgaleal lipoma
vascular
- paracaval lipoma
breast lipoma

Radiographic features

Superficial lipomas are typically well-circumscribed ovoid masses with homogeneous imaging characteristics of fat. A thin capsule, very thin septations (<2 mm), and scattered small areas of soft tissue density are common; however, avidly enhancing, thick/nodular septa or evidence of local invasion are suggestive of malignancy.

Plain radiograph

Large lipomas may be appreciated as a region of low density exerting mass effect. Calcification may be present in up to 11% of cases, although more commonly associated with well-differentiated liposarcoma ⁵.

Ultrasound

Lipomas appear as soft variably echogenic masses, commonly encountered on ultrasound. If encapsulated, the capsule may be difficult to identify on ultrasound ⁵.

~~According to a study from 2004, there~~ There is a wide range of ~~appearance~~appearances of biopsy-proven lipomas, with wide inter-reader variability ⁸:

hyperechoic: 20-52%
isoechoic: 28-60%
hypoechoic: 20%

They can also ~~tend to~~ display other ultrasound features~~, such as~~ ⁹:

no acoustic shadowing
no or minimal colour Doppler flow

Heterogeneous echotexture, more than minimal colour Doppler flow, or large size is suspicious for liposarcoma.

CT

Classic appearances are of a superficial circumscribed, low attenuation mass (typically approximately -65 to -120 HU) ^3-5 with minimal internal soft-tissue component. Again, areas of calcification may be present although are more frequently associated with well-differentiated liposarcoma ⁵.

Deeper or larger lesions may have scattered areas of internal soft-tissue density, often more apparent on CT versus MRI. These may represent areas of fat necrosis, fibrous tissue, blood vessels, or muscle fibres; these lesions cannot be confidently differentiated from liposarcoma by imaging.

Intramuscular lipomas may invade and interdigitate with the associated skeletal muscle, resulting in a characteristic striated appearance ~~which~~that may help distinguish them from liposarcoma ⁵.

MRI

MRI is the modality of choice for imaging lipomas, not only to confirm the diagnosis, which is usually strongly suggested by ultrasound and CT but also to better assess for atypical features suggesting liposarcoma. Additionally, MRI is better able to demonstrate the surrounding anatomy.

As expected, lipomas follow subcutaneous fat signal on all sequences:

T1
- high signal
- saturates on fat-saturated sequences
- no or minimal enhancement
T2
- high signal on FSE T2
- saturates on fat-saturated sequences: persistent areas of high T2 signal are worrisome

When no suspicious features are present, the diagnosis of lipoma can be made with confidence with MRI being 100% specific ¹. Similarly, if suspicious features are present, then the sensitivity of MRI is 100% ¹, although specificity is lower, as some masses with atypical features will nonetheless be lipomas.

Radiology report

Size and location should be described. Location not only includes the anatomical site but whether the mass is superficial or deep, intramuscular, etc. When reporting lipomas on MRI, the article lipoma lipoma vs well-differentiated liposarcoma covers the differentiating factors well.

Treatment and prognosis

If all characteristics are those of a simple lipoma, and no local symptoms such as pain are present, then no treatment is generally required. However, resection for cosmesis is also a reasonable indication. If any concern exists, then biopsy or excision is required, with care taken about the approach in case the lesion is malignant. Recurrence rates of 4-5% are reported (most in deeper lesions) ⁵.

Differential diagnosis

In general, there is little differential for a classic soft tissue lipoma. The main differential is:

liposarcoma
- : low-grade tumours are difficult to differentiate from lipomas, and can have a relatively benign clinical course but suffer from a high rate of recurrence ¹
normal adipose tissue

In certain locations, other fatty masses should be considered:

retroperitoneum
- , e.g. liposarcoma
- , adrenal myelolipoma
- , angiomyolipoma ~~(AML)~~
~~chest~~
- thorax, e.g. thymolipoma
, elastofibroma dorsi

Practical points

deep lipomatous masses should be assessed carefully, as they are more likely to be malignant and retroperitoneal fatty masses should be considered a well-differentiated liposarcoma until proven otherwise ⁵

~~-<li><a href="/articles/bannayan-zonana-syndrome-2">Bannayan-Zonana syndrome</a></li>~~
~~-<li><a href="/articles/cowden-syndrome">Cowden syndrome</a></li>~~
+<li>
+<a href="/articles/bannayan-zonana-syndrome-2">Bannayan-Zonana syndrome</a> <sup>10</sup>
+</li>
+<li>
+<a href="/articles/cowden-syndrome">Cowden syndrome</a> <sup>10</sup>
+</li>
+<li>
+<a href="/articles/obesity">obesity</a> <sup>10</sup>
+</li>
-</ul><h4>Clinical presentation</h4><p>Typically lipomas are subcutaneous in location and present in adulthood as a soft painless mass in the trunk or proximal extremities. They are likely to have been present for many years and may change size with weight fluctuation.</p><h4>Pathology</h4><p>Benign lipomas are circumscribed soft masses, usually encapsulated, and composed almost entirely of fat. A small amount of non-adipose components are often present, representing fibrous septa, areas of fat necrosis, blood vessels, and interposed muscle fibres. Any non-adipose components must be carefully assessed to exclude a more aggressive component. Histology demonstrates mature adipocytes with no cellular atypia or pleomorphism <sup>4</sup>.</p><p>A minority of lipomas are found in deeper locations and include intramuscular, intermuscular, intrathoracic, and retroperitoneal lipomas. These deep lipomatous masses should be assessed carefully, as they are more likely to be malignant. In fact, lesions in retroperitoneal location should be considered a well-differentiated liposarcoma until proven otherwise <sup>5</sup>.</p><p>Intramuscular lipomas have nearly identical histology to superficial lipomas; however, intramuscular lesions tend to invade the adjacent musculature and commonly lack a capsule. Thus, these are sometimes known as <strong>infiltrating lipoma</strong>. In contradistinction, intermuscular lipomas do not exhibit local invasion and tend to be lobular or dumbbell-shaped, easily separated from adjacent soft tissues during surgical resection <sup>6,7</sup>.</p><p>In 5-15% of patients, lipomas are multiple, and approximately a third of these will be familial <sup>5</sup>.</p><h5>Location</h5><ul>
+</ul><h4>Clinical presentation</h4><p>Typically lipomas are subcutaneous in location and present in adulthood as a soft painless mass in the trunk or proximal extremities. They are likely to have been present for many years and may change size with weight fluctuation.</p><h4>Pathology</h4><p>The aetiology of lipomas is unknown <sup>10</sup>. In 5-15% of patients, lipomas are multiple, and ~33% of these will be familial <sup>5</sup>.</p><h5>Macroscopic appearance</h5><p>Benign lipomas are circumscribed soft masses, usually encapsulated, and composed almost entirely of fat. Superficial lipomas are usually <5 cm whereas deep lipomas can be >20 cm <sup>10</sup>. A small amount of non-adipose components are often present, representing fibrous septa, areas of fat necrosis, blood vessels, and interposed muscle fibres. Any non-adipose components must be carefully assessed to exclude a more aggressive component. Lipomas containing metaplastic cartilage or bone are called chondrolipomas or osteolipomas respectively <sup>10</sup>.</p><h5>Microscopic appearance</h5><p>Histology demonstrates mature adipocytes with no cellular atypia or pleomorphism <sup>4</sup>.</p><p>Intramuscular lipomas have nearly identical histology to superficial lipomas; however, intramuscular lesions tend to invade the adjacent musculature and commonly lack a capsule. These are sometimes known as infiltrating lipomas. In contradistinction, intermuscular lipomas do not exhibit local invasion and tend to be lobular or dumbbell-shaped, easily separated from adjacent soft tissues during surgical resection <sup>6,7</sup>.</p><h5>Location</h5><p>Most lipomas are superficial in the subcutaneous tissues <sup>10</sup>. A minority of lipomas are found in deeper locations and include intramuscular, intermuscular, intrathoracic, and retroperitoneal lipomas. </p><ul>
+<li>tendon sheath</li>
-</ul><h4>Radiographic features</h4><p>Superficial lipomas are typically well-circumscribed ovoid masses with homogeneous imaging characteristics of fat. A thin capsule, very thin septations (<2 mm), and scattered small areas of soft tissue density are common; however, avidly enhancing, thick/nodular septa or evidence of local invasion are suggestive of malignancy.</p><h5>Plain radiograph</h5><p>Large lipomas may be appreciated as a region of low density exerting mass effect. Calcification may be present in up to 11% of cases, although more commonly associated with well-differentiated liposarcoma <sup>5</sup>. </p><h5>Ultrasound</h5><p>Lipomas appear as soft variably echogenic masses, commonly encountered on ultrasound. If encapsulated, the capsule may be difficult to identify on ultrasound <sup>5</sup>. </p><p>According to a study from 2004, there is a wide range of appearance of biopsy-proven lipomas, with wide inter-reader variability <sup>8</sup>:</p><ul>
+</ul><h4>Radiographic features</h4><p>Superficial lipomas are typically well-circumscribed ovoid masses with homogeneous imaging characteristics of fat. A thin capsule, very thin septations (<2 mm), and scattered small areas of soft tissue density are common; however, avidly enhancing, thick/nodular septa or evidence of local invasion are suggestive of malignancy.</p><h5>Plain radiograph</h5><p>Large lipomas may be appreciated as a region of low density exerting mass effect. Calcification may be present in up to 11% of cases, although more commonly associated with well-differentiated liposarcoma <sup>5</sup>. </p><h5>Ultrasound</h5><p>Lipomas appear as soft variably echogenic masses, commonly encountered on ultrasound. If encapsulated, the capsule may be difficult to identify on ultrasound <sup>5</sup>. There is a wide range of appearances of biopsy-proven lipomas, with wide inter-reader variability <sup>8</sup>:</p><ul>
~~-</ul><p>They also tend to display other ultrasound features, such as <sup>9</sup>:</p><ul>~~
+</ul><p>They can also display other ultrasound features <sup>9</sup>:</p><ul>
-</ul><p>Heterogeneous echotexture, more than minimal colour Doppler flow, or large size is suspicious for liposarcoma.</p><h5>CT</h5><p>Classic appearances are of a superficial circumscribed, low attenuation mass (typically approximately -65 to -120 HU) <sup>3-5</sup> with minimal internal soft-tissue component. Again, areas of calcification may be present although are more frequently associated with well-differentiated liposarcoma <sup>5</sup>.</p><p>Deeper or larger lesions may have scattered areas of internal soft-tissue density, often more apparent on CT versus MRI. These may represent areas of fat necrosis, fibrous tissue, blood vessels, or muscle fibres; these lesions cannot be confidently differentiated from liposarcoma by imaging.</p><p>Intramuscular lipomas may invade and interdigitate with the associated skeletal muscle, resulting in a characteristic striated appearance which may help distinguish from liposarcoma <sup>5</sup>.</p><h5>MRI</h5><p>MRI is the modality of choice for imaging lipomas, not only to confirm the diagnosis, which is usually strongly suggested by ultrasound and CT but also to better assess for atypical features suggesting <a href="/articles/liposarcoma">liposarcoma</a>. Additionally, MRI is better able to demonstrate the surrounding anatomy.</p><p>As expected, lipomas follow subcutaneous fat signal on all sequences:</p><ul>
+</ul><p>Heterogeneous echotexture, more than minimal colour Doppler flow, or large size is suspicious for liposarcoma.</p><h5>CT</h5><p>Classic appearances are of a superficial circumscribed, low attenuation mass (typically approximately -65 to -120 HU) <sup>3-5</sup> with minimal internal soft-tissue component. Again, areas of calcification may be present although are more frequently associated with well-differentiated liposarcoma <sup>5</sup>.</p><p>Deeper or larger lesions may have scattered areas of internal soft-tissue density, often more apparent on CT versus MRI. These may represent areas of fat necrosis, fibrous tissue, blood vessels, or muscle fibres; these lesions cannot be confidently differentiated from liposarcoma by imaging.</p><p>Intramuscular lipomas may invade and interdigitate with the associated skeletal muscle, resulting in a characteristic striated appearance that may help distinguish them from liposarcoma <sup>5</sup>.</p><h5>MRI</h5><p>MRI is the modality of choice for imaging lipomas, not only to confirm the diagnosis, which is usually strongly suggested by ultrasound and CT but also to better assess for atypical features suggesting <a href="/articles/liposarcoma">liposarcoma</a>. Additionally, MRI is better able to demonstrate the surrounding anatomy.</p><p>As expected, lipomas follow subcutaneous fat signal on all sequences:</p><ul>
-</ul><p>When no suspicious features are present, the diagnosis of lipoma can be made with confidence with MRI being 100% specific <sup>1</sup>. Similarly, if suspicious features are present, then the sensitivity of MRI is 100% <sup>1</sup>, although specificity is lower, as some masses with atypical features will nonetheless be lipomas.</p><h4>Treatment and prognosis</h4><p>If all characteristics are those of a simple lipoma, and no local symptoms such as pain are present, then no treatment is generally required. However, resection for cosmesis is also a reasonable indication. If any concern exists, then biopsy or excision is required, with care taken about the approach in case the lesion is malignant. Recurrence rates of 4-5% are reported (most in deeper lesions) <sup>5</sup>.</p><h4>Differential diagnosis</h4><p>In general, there is little differential for a classic soft tissue lipoma. The main differential is:</p><ul>
+</ul><p>When no suspicious features are present, the diagnosis of lipoma can be made with confidence with MRI being 100% specific <sup>1</sup>. Similarly, if suspicious features are present, then the sensitivity of MRI is 100% <sup>1</sup>, although specificity is lower, as some masses with atypical features will nonetheless be lipomas.</p><h4>Radiology report</h4><p>Size and location should be described. Location not only includes the anatomical site but whether the mass is superficial or deep, intramuscular, etc. When reporting lipomas on MRI, the article lipoma <a href="/articles/lipoma-vs-well-differentiated-liposarcoma">lipoma vs well-differentiated liposarcoma</a> covers the differentiating factors well. </p><h4>Treatment and prognosis</h4><p>If all characteristics are those of a simple lipoma, and no local symptoms such as pain are present, then no treatment is generally required. However, resection for cosmesis is also a reasonable indication. If any concern exists, then biopsy or excision is required, with care taken about the approach in case the lesion is malignant. Recurrence rates of 4-5% are reported (most in deeper lesions) <sup>5</sup>.</p><h4>Differential diagnosis</h4><p>In general, there is little differential for a classic soft tissue lipoma. The main differential is:</p><ul>
-<a href="/articles/liposarcoma">liposarcoma</a><ul><li>low-grade tumours are difficult to differentiate from lipomas, and can have a relatively benign clinical course but suffer from high rate of recurrence <sup>1</sup>
~~-</li></ul>~~
+<a href="/articles/liposarcoma">liposarcoma</a>: low-grade tumours are difficult to differentiate from lipomas, and can have a relatively benign clinical course but suffer from a high rate of recurrence <sup>1</sup>
~~-<li>retroperitoneum<ul>~~
~~-<li><a href="/articles/adrenal-myelolipoma">liposarcoma</a></li>~~
~~-<li><a href="/articles/adrenal-myelolipoma">adrenal myelolipoma</a></li>~~
~~-<li><a href="/articles/angiomyolipoma">angiomyolipoma (AML)</a></li>~~
~~-</ul>~~
+<li>retroperitoneum, e.g. <a href="/articles/adrenal-myelolipoma">liposarcoma</a>, <a href="/articles/adrenal-myelolipoma">adrenal myelolipoma</a>, <a href="/articles/angiomyolipoma">angiomyolipoma</a>
~~-<li>chest<ul><li><a href="/articles/thymolipoma">thymolipoma</a></li></ul>~~
+<li>thorax, e.g. <a href="/articles/thymolipoma">thymolipoma</a>, <a href="/articles/elastofibroma-dorsi">elastofibroma dorsi</a>
~~-</ul>~~
+</ul><h4>Practical points</h4><ul><li>deep lipomatous masses should be assessed carefully, as they are more likely to be malignant and retroperitoneal fatty masses should be considered a well-differentiated liposarcoma until proven otherwise <sup>5</sup>
+</li></ul>

Updates to Synonym Attributes

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parosteal","thumbnail":"https://prod-images-static.radiopaedia.org/images/5071949/98073b8099099e190e63946e301c6a_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":7301776,"studyId":30055,"caseSlug":"lipoma-of-the-neck-2","caption":"Case 20: subcutaneous lipoma in nape of neck","thumbnail":"https://prod-images-static.radiopaedia.org/images/7301776/8dd427ac1cf2dad895533ad09c2f7c_big_gallery.jpg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":7267766,"studyId":29996,"caseSlug":"intramuscular-lipoma-of-deltoid-1","caption":"Case 21: intradeltoid lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/7267766/6a5d6462d93340b2687aa4c93791cc_big_gallery.jpg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":8253161,"studyId":31669,"caseSlug":"intermuscular-lipoma-of-the-neck","caption":"Case 22: intermuscular lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/8253161/4e4e954c674f51001950e5f9b13c84_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":834391,"studyId":13278,"caseSlug":"lipoma-of-thigh","caption":"Case 23: lipoma of thigh","thumbnail":"https://prod-images-static.radiopaedia.org/images/834391/b392f94b913211669d9799c69dc4389d924f7ab11df96640c7033357428af3fe_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":11664580,"studyId":36406,"caseSlug":"giant-lipoma-of-scalp","caption":"Case 24: large lipoma of scalp","thumbnail":"https://prod-images-static.radiopaedia.org/images/11664580/9f4e829a15741b1d9c307406d5f896_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":13971221,"studyId":39677,"caseSlug":"parotid-lipoma-2","caption":"Case 25: parotid lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/13971221/78d9bdd0a8d5321004a1975a80ad2a_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":51122719,"studyId":80175,"caseSlug":"large-lipoma-thigh","caption":"Case 26: thigh","thumbnail":"https://prod-images-static.radiopaedia.org/images/51122719/0e883109b78b85c156db039ffedd5b_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":2980959,"studyId":21919,"caseSlug":"lipoma-arm","caption":"Case 27: arm ","thumbnail":"https://prod-images-static.radiopaedia.org/images/2980959/16749536e218b42d4e6ca2e4e02a46_big_gallery.jpg","isStack":false,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":52569222,"studyId":89230,"caseSlug":"posterior-interosseous-neuropathy-secondary-to-lipoma-1","caption":"Case 28: lipoma causing posterior interosseous neuropathy","thumbnail":"https://prod-images-static.radiopaedia.org/images/52569222/8f47bec0555e1f7513a43fd9795df6_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"probable"},{"imageId":55596061,"studyId":109602,"caseSlug":"retroperitoneal-lipoma","caption":"Case 29: retroperitoneal lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/55596061/110066_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":56692753,"studyId":115295,"caseSlug":"neck-intermuscular-lipoma","caption":"Case 30: Neck intermuscular lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/56692753/fd339979dafe34d04e39a0fa8c4fef667228520e68ac4244e9f487c65762f315_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":59345227,"studyId":125184,"caseSlug":"lipoma-11","caption":"Case 31","thumbnail":"https://prod-images-static.radiopaedia.org/images/59345227/24980c633326d6854a7bd71f9231310b00a0e043dd617d49ef1191cb95d78829_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":60147511,"studyId":128862,"caseSlug":"neck-lipoma-1","caption":"Case 32","thumbnail":"https://prod-images-static.radiopaedia.org/images/60147511/b538e1fc65ae102db5622322bf2e96e4c0281d000e5866f5fb44dacb358d0e66_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":61158538,"studyId":132240,"caseSlug":"giant-gastric-lipoma","caption":"Case 33: giant gastric lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/61158538/8ab0b0782ffc10012477768f29c0da3b19c7b2840592e1660e17cadd041766e6_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":60052931,"studyId":128412,"caseSlug":"splenic-lipoma","caption":"Case 34: splenic lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/60052931/b73f8847a7f81324838430c55d6727e636fc62959269e9ed779539603296f42a_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":62182734,"studyId":136162,"caseSlug":"duplicated-ivc-3","caption":"Case 35: erector spinae intramuscular lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/62182734/3bc4de0420d55e49f0dee5fb345e11775fd83f589c8c13f5a259627d07e4fb2f_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":62863282,"studyId":138940,"caseSlug":"giant-palmar-lipoma","caption":"Case 36: palmar lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/62863282/639d7f293baa71cd7c23487a2fa3ad7c2158c83e4679c25a78d565f0a077c666_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":62907737,"studyId":139099,"caseSlug":"submandibular-lipoma","caption":"Case 37: Submandibular lipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/62907737/634d410415a9e61ad29cf56d5c0f5a63433c487a21337b86457a3fcd5e19dcde_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":63592560,"studyId":142064,"caseSlug":"thigh-lipoma-1","caption":"Case 38","thumbnail":"https://prod-images-static.radiopaedia.org/images/63592560/5a4bd906153409df8fc5a23b972257d71e0a8a43ab9cc33bfe3cc430a1e80818_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"}],"ddx_inclusions":[{"imageId":23721,"studyId":8478,"caseSlug":"liposarcoma","caption":"Liposarcoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/23721/be61311b19994c05d5cfb45a5f793b_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":26542,"studyId":7906,"caseSlug":"renal-angiomyolipoma-5","caption":"Angiomyolipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/26542/dce32de1cc9e81538ba985111d5c27_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":28039,"studyId":7960,"caseSlug":"adrenal-myelolipoma","caption":"Adrenal myelolipoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/28039/eb6176eca035a328a7986eef906553_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":53918330,"studyId":99674,"caseSlug":"liposarcoma-10","caption":"Liposarcoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/53918330/880011_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":58753343,"studyId":122194,"caseSlug":"post-traumatic-fat-necrosis-of-the-anterior-abdominal-wall","caption":"Post traumatic fat necrosis of the anterior abdominal wall","thumbnail":"https://prod-images-static.radiopaedia.org/images/58753343/2._big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"}],"lang":"us"}