Hygroma, derived from the Greek hygros (moist) and oma (tumor), is a term which has often been used loosely to include various types of cysts containing a thin watery fluid. The designation cavernous lymphangioma has frequently been applied to the cystic form of this tumor. In a stricter sense, hygroma should be limited to multilocular cystic tumors of benign neoplastic nature which have a lymphatic origin and whose cavities are lined with true endothelium. These tumors originate, for the most part, in the neck and axilla and are then designated as hygroma colli cysticum and hygroma axillare. Occasional cases of hygroma occurring in the groin or in the retroperitoneal space have been reported. Since these cystic tumors are relatively rare, the descriptions in the literature are limited in many instances to case reports, which are often incomplete, contradictory and unsupported by records of careful pathologic examination. The manner of growth