Learning objectives
1.
To review imaging features of the different locations in which melanoma can metastasize.
2.
To describe thedifferent manifestations metastatic melanoma can takedepending on the organ where they occur.
Background
Melanoma is the most serious form of skin malignancy with an incidence that increases with age,
exposure to ultraviolet radiation,
and is influenced by genetic factors.
Melanoma is an aggressive neoplasm that derives from melanocytes.
These cells originate from the neural crest cells that migrate to the skin during early fetal stages,
through central nervous system pathways (fig.
1).
The majority of melanomas grow from preexisting benign nevi.
Melanomamortality rate depends on the stage of the disease at the time of diagnosis,
and has a...
Findings and procedure details
The most used imaging technique for the extension study and the follow-up of these patients is CT.
However,
for the detection of cerebral metastases or when the tomographic study is inconclusive,
MRI is the technique of choice due to its superiortissue characterization.
The ultrasound is limited to the assessment of the scar area and the study of locoregional lymphaticchains.
PET-CT is also useful in the monitoring of maetastatic melanoma because of its ability to assess the entire body in a single study,
however it has...
Conclusion
Melanoma is an agressive form of skin malignancy that can metastasize to any organ and it may spread in an unpredictable manner in advanced stages.
Unique characteristics of density and signal intensity of melanin in CT and MRI,
its tendency to bleed,
ultrasound attenuation and hypervascularity can give radiologists essential clues to detect melanoma metastasis.
References
Ginanni,
B.,
Vallini,
V.,
Marchetti,
M.,
Lauretti,
D.
L.,
Cerri,
F.,
Bozzi,
E.,
Caramella,
D.,
Bartolozzi,
C.
(2012).
Usual and unusual imaging findings in Metastatic Melanoma (MM).ECR 2012,
1–50.
http://doi.org/10.1594/ecr2012/C-0925
Kim,
K.
W.,
Ha,
H.
K.,
Kim,
A.
Y.,
Kim,
T.
K.,
Kim,
J-S.,
Yu,
C.
S.,
Park,
S.
W.,
Park,
M-S,
Kim,
H.
J.,
Kim,
P-N.,
Kim,
J.
C.,
Lee,
M-G.
(2004).
Primary malignant melanoma of the rectum: CT findings in eight patients.Radiology,
181–186.
http://doi.org/10.1148/radiol.2321030909
Martel,
Jean Pierre A.,
McLean,
Carolyn A.,
Rankin,
Richard...