Recurrent Plunging Ranula Due to a Sublingual Ectopic Gland: A Rare Clinical Entity

Abstract

Ranula is a benign cystic lesion caused by the escape and collection of salivary mucus. Classically, it is divided into simple ranulas, a cystic mass in the floor of the mouth, and diving/plunging/cervical ranulas, a submandibular mass without apparent intraoral involvement. Although plunging ranula is a well-documented cause of neck swelling, its association with the presence of ectopic sublingual glands is extremely rare, with less than five cases reported. Other cervical cystic lesions may have the same clinical aspect; therefore, advanced diagnostic techniques like a CT scan or MRI play a critical role in early diagnosis. Different approaches have been used to treat ranulas, including non-invasive, minimally invasive, and surgical techniques. The purpose of this paper is to highlight a case report of a giant plunging ranula due to an anatomical aberration of the right sublingual gland, along with a significant literature review.

Keywords: ectopic gland; mouth floor; plunging ranula; salivary gland; tail sign; transoral surgical approach.

Figure 1. Extraoral view: right and left submandibular swelling

Figure 2. Intraoral view: swelling in one side of the lingual frenum (right floor of the mouth)

Figure 3. (A) Coronal CT image showing hypodense fluid collection above (white star) and below (blue star) the mylohyoid muscle. (B) Axial CT image with contrast, showing well-defined swelling in the right and left submandibular region (white star). (C) Axial CT image showing “tail sign” phenomenon (white arrow)

Figure 4. (A) Axial CT image showing the accessory lobe of the right sublingual gland (white arrow). (B) Coronal CT image showing accessory lobe of the right sublingual gland (blue arrow)

Figure 5. Resected specimen of the right sublingual gland with a white solid nodule (white arrow)