Bilateral Plunging Ranulas in South Auckland: Evidence for a Genetic Basis

Objectives We present a series of bilateral plunging ranula patients to examine the etiology, diagnosis, treatment, and prognosis of this condition. Methods A retrospective chart review was performed on all cases of plunging ranula treated at the Department of Otolaryngology–Head and Neck Surgery, Counties Manukau District Health Board, New Zealand, between 2001 and 2019. Results There were 17 patients with bilateral plunging ranulas from a total of 187 plunging ranula patients. Eight patients were of Pacific Island descent; six were Maori; and three were Asian. There were no European patients with bilateral plunging ranulas. There were three types of bilateral plunging ranula patients: 1) Metachronous plunging ranulas— Five patients presented with a unilateral plunging ranula with no evidence of a contralateral plunging ranula on initial imaging. Despite negative contralateral imaging findings, these patients developed a clinically evident contralateral plunging ranula 21 to 61 months later. 2) Synchronous plunging ranulas detected on imaging— Eight patients presented with a clinically evident unilateral plunging ranula but also had a contralateral plunging ranula detected on imaging. 3) Clinically evident synchronous plunging ranulas— Four patients presented with bilateral clinically evident plunging ranulas, which were also evident on imaging. Twelve patients underwent bilateral transoral sublingual gland excision and plunging ranula evacuation. Conclusion All patients with a unilateral plunging ranula should be advised of the potential for developing contralateral disease, and this should be emphasized in patients of Pacific Island, Maori, and Asian descent. Level of Evidence 4 Laryngoscope , 131:73–77, 2021