Lipoma: Clinical sciences

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Introduction0:00–0:41

Lipomas are benign fatty neoplasms that can occur anywhere in the body. While most are solitary, superficial, and limited to the subcutaneous space, some can arise within the deeper soft tissue like the muscle.
Sometimes, systemic conditions like lipomatosis can lead to multiple, diffuse or recurrent lipomas. Usually, small and painless lipomas do not require any medical treatment.
However, when the mass causes functional or cosmetic dysfunction or is suspicious for malignancy, treatment for removal should be considered.

History & Physical - Subcutaneous lipoma0:41–2:48

Alright, when assessing a patient with a chief concern suggestive of lipoma, your first step is to obtain a focused history and physical examination.
Most subcutaneous lipomas are asymptomatic, and are noticed incidentally by the patient on inspection or palpation. History will usually reveal a painless, slow-growing, small, soft, and solitary mass found on the trunk or proximal extremities.
Now, upon a physical exam, you can expect to find a superficial subcutaneous mass that is soft, round, mobile, and well-localized.
The mass typically feels doughy with smooth, slippery edges. If these findings are present, you can make your diagnosis of a subcutaneous lipoma.
Superficial lipomas can be diagnosed clinically, so additional work up is not necessary. Your treatment for superficial lipomas depends on the size.
For example, small lipomas often can be managed with observation without any intervention; however, if the mass is large, like greater than 5 cm, or if it causes cosmetic concerns, it can be surgically excised.Here's a clinical pearl!
Lipomas can occur anywhere in adipose tissue, including the subcutaneous, intramuscular, gastrointestinal tract, and retroperitoneum.
For subcutaneous masses, slippage sign is characteristic for lipoma. It can be elicited by gently sliding fingers off the tumor feeling for its slippery edge, or capsule.
Keep in mind that lipomas located deeper within the soft tissue might not elicit this sign very clearly, or at all. Additionally, a lipoma in the GI tract is a very rare type that can arise in the submucosa of the esophagus, stomach, and small intestine.
While GI lipomas are benign, it can cause luminal obstruction requiring surgical resection.Alright, now let’s talk about another type of lipomas that can be found in deeper tissues.

Intramuscular lipoma2:48–5:21

On history, you can expect the patient to report a painless, slow-growing, small, solitary mass often on the proximal extremity, like the upper arm or thigh.
Patients might also report muscle weakness, pain on active movement, or even decreased range of motion of the affected extremity.
Your physical exam might reveal a deep, round, partially mobile mass that is poorly localized mostly due to the depth of the mass within the soft tissue.
Depending on the location of the mass relative to its nearby structure, you might find a reduced distal pulse, tenderness of the mass on palpation, or even paresthesia from compression of the adjacent nerves.
If any of these characteristics are present, you should suspect a deep intramuscular lipoma.Now for deep intramuscular lipomas or tumors you can obtain an ultrasound, followed by CT scan or MRI to better visualize the mass, and a core needle biopsy if it's suspicious for malignancy.
On imaging, you will see a well-circumscribed, fat-containing mass deep to the superficial fascia. If a core needle biopsy was obtained, histopathology results showing adipocytes infiltrated between muscle cells will confirm your diagnosis.
Your management for these lesions can include observation for small asymptomatic lipomas, or complete surgical excision for large, symptomatic, cosmetically concerning lipomas or for lipoma with unclear pathology.Here is another clinical pearl!
As a general rule, biopsies are often performed for large lipomas or masses that are suspicious for malignancy like liposarcoma.
Malignant masses are clinically different from benign lipomas as malignant lesions tend to be hard and non-mobile, tethered to the underlying fascia.
While most lipomas can be excised easily with their capsule intact, malignant lesions require a complex resection with adequate margins.
Excision is considered curative for most patients with benign lipomas, however, there is 1 to 2% chance that it might recur in the future.
Okay, let’s discuss our final type of lipoma. On history, the patient will often report gradual development of multiple small masses in various parts of their body.

Diffuse lipomatosis5:21–6:49

Depending on the location and size of the masses, the patient might report pain. In addition, the patient might have a history of genetic syndromes like familial multiple lipomatosis, Gardner syndrome, familial adenomatous polyposis, or multiple systemic lipomatosis.
Multiple systemic lipomatosis, also known as Madelung disease, is a rare lipid storage disorder that causes an abnormal accumulation of subcutaneous fat leading to the formation of small lipomas all over the body.
In general, physical examination typically shows multiple mobile, soft masses of varying sizes that are diffuse and can be tender on palpation.
If you see these findings, your diagnosis is diffuse lipomatosis. The treatment options are mainly based on patient preference.
They include observation for small asymptomatic lipomas; or surgical excision, liposuction, injection lipolysis for larger or cosmetically concerning lesions; as well as any additional work up or management of the underlying genetic syndrome.Alright, as a quick recap… A lipoma is a common benign fatty tumor that can occur anywhere in the body.

Review6:49–7:27

The three main types of lipomas include superficial subcutaneous lipoma, deep intramuscular lipoma, and diffuse lipomatosis.
Most subcutaneous lipomas are small and asymptomatic, so they can be managed with observation without any intervention; while surgical excision can be performed for large or symptomatic lipomas, as well as lesions that are diagnostically ambiguous, or those that cause functional or cosmetic concerns.
Lipoma: Video, Causes, and Symptoms | Osmosis