Diagnostic Difficulties of Plunging Ranula: A Review of 18 Cases

Despite advancements in imaging techniques and cytological analysis, plunging ranula remains a challenging surgical, radiologic, and pathologic phenomenon. Of the 18 patients we evaluated at our institution, we highlight three cases that illustrate the high rate of misleading imaging and cytological results when assessing plunging ranula.

Imaging results, biopsy findings, operative techniques, and pathological reports were reviewed from patients who had either a preoperative or postoperative diagnosis of ranula and underwent surgery by a single head and neck surgeon at a tertiary care center.

Of the 18 identified patients, computed tomography was correct on preoperative imaging 73% of the time and magnetic resonance imaging was correct on preoperative imaging 71% of the time. Two patients underwent preoperative ultrasound and their ultrasound reports did not accurately diagnose the presence of a ranula. Two patients underwent preoperative fine needle aspiration biopsy due to inconclusive preoperative imaging, in which results suggested either a ranula or epidermal cyst. Both ultimately did not match the final pathology. Three of eighteen patients (17%) underwent an inappropriate initial surgery due to incorrect imaging diagnoses and/or biopsy findings.

Despite use of preoperative modalities to distinguish plunging ranula from other cystic floor of mouth lesions, surgeons must be aware that no workup modality is fully precise. The potential for revision surgery must be included in all preoperative discussions for presumed plunging ranula.

4 Laryngoscope, 134:2689-2696, 2024.