What is the Difference Between Hematoma and Morel Lavallée Lesion?

A hematoma and a Morel-Lavallée lesion are both types of skin injuries, but they have distinct differences:

Hematoma: A hematoma is a collection of blood outside a blood vessel, occurring when an injury causes blood to collect and pool under the skin. It is typically deeper, less well-defined, and less fluctuant than a Morel-Lavallée lesion.
Morel-Lavallée Lesion: This is a closed degloving soft tissue injury, resulting from the abrupt separation of skin and subcutaneous tissue from the underlying fascia. It is characterized by a potential space filled mainly by serous fluid, and it feels superficial compared to a hematoma. Morel-Lavallée lesions can be misdiagnosed as hematomas due to their similar appearance.

Some key differences between hematomas and Morel-Lavallée lesions include:

Cause: Hematomas are caused by blood collecting under the skin due to injury, while Morel-Lavallée lesions result from the separation of skin and subcutaneous tissue from the underlying fascia.
Location: Hematomas are typically deeper, while Morel-Lavallée lesions occur at the interface between subcutaneous fat and deep fascia.
Fluctuance: Morel-Lavallée lesions are characterized by significant fluctuance, while hematomas are less fluctuant.

The differential diagnosis of Morel-Lavallée lesions includes post-traumatic injuries like fat coagulopathy-related hematomas and rarely, post-traumatic early-stage myositis ossificans with diffuse signal intensity.

On this page

What is the Difference Between Hematoma and Morel Lavallée Lesion?

Comparative Table: Hematoma vs Morel Lavallée Lesion

Here is a table comparing the differences between a hematoma and a Morel Lavallée lesion:

Feature	Hematoma	Morel Lavallée Lesion
Definition	A collection of blood outside a blood vessel, occurring when an injury causes blood to collect and pool under the skin	A soft tissue degloving injury, occurring when an extensive section of the skin is completely torn off, with separation of skin and superficial fascia from the deep fascia
Causes	Injuries due to trauma, aneurysms, anticoagulants, viral infections, and orthopedic injuries such as fractures	High-energy trauma, orthopedic fractures, and shearing forces
Symptoms	Pain, swelling, palpable fluctuant collection over the injured area, and hypoesthesia	Pain, swelling, and possible fluid collection between the subcutaneous fat and underlying fascia
Diagnosis	Physical examination, imaging techniques such as X-ray, ultrasound, or MRI	Ultrasound is the imaging method of choice; MRI can be useful in selected cases
Treatment	Depends on the size, location, and underlying cause of the hematoma, and may include compression, elevation, ice packs, painkillers, or surgical intervention	Treatment options include rest, ice, compression, elevation, painkillers, and surgical intervention in severe cases
Risk of Infection	Risk of infection is a common complication of hematomas	Risk of infection is a potential complication, although less common than in hematomas

Guilherme Mazui

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.