Pediatric Vulvar Superficial Angiomyxoma: A Case Report With Clinical, Radiological, and Anatomopathological Characterization and a Comprehensive Review of the Literature.

Superficial angiomyxoma is characterized as a benign, slow-growing vascular cutaneous myxoma. A 6-year-old Arab girl with no medical history presented with a vulvar tumor located on the left labia majora. The lesion was present since birth, but it had significantly increased over the last 6 months. She did not have any associated symptoms. Physical examination revealed an exophytic tumor of the left labia majora, which measured 5 cm in its major axis. Doppler ultrasound study showed a mass with abundant arterial and venous vascularization, and magnetic resonance imaging showed a highly vascular contrast-enhanced mass with well-delimited margins, which depended on the labia majora. A macroscopically complete resection was performed, achieving a tension-free primary closure. Histologically, the lesion was characterized as a well-demarcated superficial tumor with thin-walled vessels and myxoid stroma, S100 (-), CD34 (+), vimentin (+), and actin (+). The final histopathological diagnosis was superficial angiomyxoma. The literature review of this entity in the pediatric population shows a predominance of this lesion in the vulvar location. Local recurrence has been described. Loss of PRKAR1A expression may be involved in the pathogenesis of superficial angiomyxoma.