Giant benign lymphangioendothelioma with positive expression of Wilms tumor 1: A case report

Benign lymphangioendothelioma (BL, acquired progressive lymphangioma) is a rare, slow‐growing lymphatic tumor, first described 40 years ago, with fewer than 50 published cases. Clinically, it presents as a skin‐colored or erythematous patch. Definitive diagnosis requires histopathological examination. The immunohistochemical staining profile is still controversial regarding Wilms tumor 1 (WT1) expression, a marker of proliferative and neoplastic, rather than malformative nature. Here, we report a case of a 60‐cm‐long BL on the breast of an adult female. Biopsy revealed irregular vascular spaces dissecting the collagen bundles lined by swollen endothelial cells but without cellular atypia. Positivity for podoplanin (D2‐40), CD31, and WT1 was observed, supporting the neoplastic nature of this lesion. Dermatologists and pathologists must be aware of this entity for early diagnosis and treatment.