Superficial angiomyxoma of the skin.

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.

Case presentation

A 72-year-old man with a history of melanoma in situ presented for his regular follow-up visit. The routine clinical examination revealed a pinkish-red nodule on the lower back. The nodule was not present in the previous visit held six months earlier (Figures 1, A and B).

Figure 1.

Superficial angiomyxoma. Clinical images. [Copyright: ©2016 Abarzúa-Araya et al.]

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).

Figure 2.

Superficial angiomyxoma. Dermoscopic image. [Copyright: ©2016 Abarzúa-Araya et al.]

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). The findings were diagnostic of superficial angiomyxoma.

Figure 3A & B.

Superficial angiomyxoma. Histologic images. [Copyright: ©2016 Abarzúa-Araya et al.]

Conclusions

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. reported several cases of SA without evidence of Carney’s complex. In 1999 Calonje et al. reported the clinicopathological and immunohistochemical features of SA as an independent disease [1,5]. In 2014 Green et al. reported the dermoscopic features of SA for the first time and described “the red planet sign”—a red, translucent, globular exophytic lesion with arborizing vessels that looks like a blood moon during recent lunar eclipses [6]. 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. Our case suggests that SA should be added in this list. However, since these dermoscopic findings are highly unspecific, a nodule dermoscopically characterized by predominantly dotted vessels should be promptly excised to rule out melanoma.