The MLL first described by a French physician
Maurice Morel Lavallée in 1853 is a closed
degloving injury involving separation of the skin
and subcutaneous fat from the underlying fascia.[
2,
3]
The acute trauma, typically due to a blunt shearing
force applied across the surface of the skin, creates
a potential space between the subcutaneous fat and
fascia which fills with a mixture of hemorrhage, fat,
and lymphatic fluid due to disruption of bridging
vessels and lymphatic channels.[
3] Vanhegan et al.[
1]
and Hak et al.[
3] reported trochanteric, pelvic, flank
and knee regions as the most common locations for
these lesions. On the other hand, MLLs are rarely
seen in multiple regions.[
4]
Morel-Lavallée lesions present within a few hours
to 13 years.[5] They are usually with underlying
fractures and mostly unilateral. Patients may suffer
from pain, swelling and stiffness. Physical examination
reveals a fluctuant boggy mass under skin causing
contour deformity with or without discoloration. Unresolved hematomas may also become persistent
with encapsulation.
Morel-Lavallée lesions can be detected by
ultrasonography. However, MRI is the best choice
to determine the lesion type and chronicity.[6] On
MRI, acute or subacute fluid collections containing a
large amount of methemoglobin may be hyperintense
on T1- and T2-weighted imaging. In this case, MRI
showed acute fluid collection-related hyperintense
lesions.
The differential diagnoses for acute lesions include
hematomas, abscesses, fat necrosis, and soft tissue
neoplasms, whereas the differential diagnosis is
expanded in chronic collections which are better
marginated and more homogeneous including seromas,
bursitis, and lymphoceles.[7]
The skin receives its blood supply from the
underlying fascia, whereas perfusion is dependent on
the dermal and subcutaneous vascular plexus after the
separation from the fascia. In cases of such injuries, expanding hematoma may lead to skin necrosis acutely
or in a delayed fashion, if not promptly drained.
Treatment options include application of compression
banding, percutaneous or open surgical drainage with
debridement, and irrigation and suction drainage with
or without injection of sclerosing agents followed by
pressure therapy.[5]
In conclusion, in our case, the lesion was atypically
located including both thigh, knee and calf regions,
and the initial symptoms and findings were similar
with deep vein thrombosis. The diagnosis of
Morel-Lavallée lesions should be particularly kept in
mind by the cardiovascular surgeons and orthopedists,
when venous Doppler ultrasonography reveals normal
findings.
Declaration of conflicting interests
The authors declared no conflicts of interest with
respect to the authorship and/or publication of this
article.
Funding
The authors received no financial support for the
research and/or authorship of this article.
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