Massive adult cystic lymphangioma of the breast.

Adult cystic lymphangiomas are exceedingly rare tumors resulting from malformation of the lymphatic vessels. Like their pediatric counterparts, these lesions almost exclusively involve the head and neck. However, adult cystic lymphangiomas have been reported in several organs. Those involving the breast are exceptionally rare, with only a few reported instances. Here, we present the case of a 27-year-old woman who attended a surgical breast clinic with a 2-year history of a large, disfiguring left breast mass. Pathology was consistent with adult cystic lymphangioma of the breast. Measuring 21.0 × 20.0 × 6.0 cm3, this represents the second largest of its kind and the largest reported case in an African American patient.