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Paper text:
a 72-year - old man with a history of melanoma in situ presented for his regular follow - up visit .
the nodule was not present in the previous visit held six months earlier ( figures 1 , a and b ) .
the dermoscopic examination revealed a nonpigmented lesion characterized by a polymorphous vascular pattern , consisting of dotted and short curved linear vessels on a red - pinkish background .
the latter unspecific pattern did not allow a definite diagnosis , prompting us to excise the nodule ( figure 2 ) .
on low power examination the lesion was well circumscribed and involved the reticular dermis ( figure 3a ) . at higher magnification ,
the extensive myxoid change was evident ; cellularity was inconspicuous and vascularity consisted of small , thin - walled vessels ( figure 3b ) .
sa was initially described by carney et al . in 1985 in association with carney s complex syndrome , a rare autosomal dominant disorder characterized by neoplasia involving the heart , central nervous system , and endocrine organs . in 1998 allen et al .
calonje et al . reported the clinicopathological and immunohistochemical features of sa as an independent disease .
in 2014 green et al . reported the dermoscopic features of sa for the first time and described  the red planet signa red , translucent , globular exophytic lesion with arborizing vessels that looks like a blood moon during recent lunar eclipses .
in contrast , in our case , the patient presented with a pinkish - red nodule on the lower back , not a polypoid lesion .
additionally , dermoscopy did not show the red planet sign , thus we believe that this sign may be highly unspecific or anecdotic .
we did not perform an echocardiogram or other tests because our patient lacked skin pigmentation , mucosal lesion , other cutaneous tumors or family history of myxomas .
although spitz nevus and amelanotic melanoma come first in the list of differential diagnoses of nonpigmented nodular lesions displaying predominantly dotted vessels under dermoscopy , several other less common tumors might exhibit a similar pattern .
however , since these dermoscopic findings are highly unspecific , a nodule dermoscopically characterized by predominantly dotted vessels should be promptly excised to rule out melanoma .
superficial angiomyxomas ( sa ) of the skin are rare benign cutaneous tumors of soft tissue composed of prominent myxoid matrix and numerous blood vessels . 
 sa are more common in males [ 1 ] and they are usually located on the trunk but can also appear on the lower limbs , head , neck and genitalia [ 2,3 ] . 
 treatment is surgical , the total excision is curative , but local recurrence is possible [ 4 ] . 
 herein we present a 72-year - old patient with a history of melanoma in situ , with a new lesion on the lower back .