[Diving ranula. A rare disease picture].

The case of a 24-year-old woman with a plunging ranula is reported. Primarily, the patient noticed extensive swelling of the neck, which had developed 3 months previously. The polycystic, firmly attached tumor and the sublingual and submandibular glands of the right side of the neck were surgically removed. Pathological examination showed a retention cyst by means of a plunging ranula. The etiology, pathogenesis, clinical aspect and diagnostic procedures for the plunging ranula are described. Various therapeutic possibilities are discussed in regard to their value. We prefer surgical treatment with a histological examination to verify the diagnosis. The plunging ranula originates on the sublingual gland; therefore, its simultaneous extirpation is recommended to avoid recurrences. In extensive cases, the additional removal of the submandibular gland can be advised.