The plunging ranula: diagnostic difficulties and a less invasive approach to treatment.

Plunging ranulas arise when a simple ranula extends beyond the floor of the mouth into the neck. Diagnosis is difficult even with modern imaging techniques as they mimic other neck lesions, and traditional treatment involves enucleation of the cyst from the neck. Despite this invasive surgery they tend to recur. We describe a less invasive approach to treatment and review the diagnostic pitfalls. From 2002 to 2011, eight patients presented with a plunging ranula. They were split into two groups: those for whom an incorrect diagnosis was made and those where a less invasive treatment approach was employed. Three patients were misdiagnosed with cervical lymphangioma and had inappropriately invasive surgery. Five patients with established plunging ranulas were treated using an intraoral approach alone, eliminating the need for a cervical incision. Misdiagnosis of a plunging ranula leads to extensive and unnecessary surgery. We propose an algorithm to simplify investigation that employs a low threshold for fine-needle aspiration cytology. The cases presented indicate that these lesions can be managed by a less invasive procedure than currently practised.