A 22-year-old woman presented to the ED with swelling under her tongue. She reported that it had quickly developed over a few hours and extended to the left side of her neck. She had no difficulty breathing or fever, but reported dysphagia and difficulty speaking. She also had no food or drug allergies and no dental pain, but had had her wisdom teeth extracted a few months earlier. After that extraction, she said she had similar but much less swelling that spontaneously resolved after two weeks.
Her vital signs included a temperature of 36.9°C, a blood pressure of 122/79 mm Hg, a pulse of 110 bpm, a respiratory rate of 29 bpm, and an oxygen saturation of 99% on room air. She appeared anxious, and was alert and sitting upright on a stretcher suctioning her saliva. She had no swelling or facial asymmetry, and her trachea was midline. She was tachypneic but breathing comfortably with no audible stridor.
She had moderate left (greater than right) sublingual cystic swelling that was soft and without purulent drainage or bleeding. Her tongue was displaced posteriorly with limited tongue protrusion, but she had normal lateral movement of the tongue. She also had left submandibular neck swelling that was soft and mildly tender to palpation. There was no skin erythema or induration, and she was able to lie flat during the exam without respiratory distress.
What urgent procedures are needed? What further diagnostic workup is needed?
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Diagnosis: Plunging Ranula
Ranulas and mucoceles are among the most common disorders of the salivary glands and the most common soft tissue lesions of the oral cavity. Ranulas and mucoceles form a pseudocyst when salivary gland secretions (mucous) dissect into the soft tissues surrounding the salivary gland, often caused by trauma to the salivary ducts. (J Oral Maxillofac Pathol. 2014;18[Suppl 1]:S72; https://bit.ly/2KrfQ4f.)
The causative trauma is often eating, dental procedures, or external blunt trauma (biting lips). Mucoceles are more common (2.4 cases per 1000 people), and involve the minor salivary glands. Ranulas are less common (0.2 cases per 1000 people), involve the major salivary glands, and originate from the sublingual glands more often than the submandibular glands. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004;98:274).
Mucoceles often form on the mucosal side of the lower lip and mouth due to trauma to the minor salivary ducts. Ranulas can be simple (oral) when limited to the floor of the oral cavity superior to the mylohyoid muscle or plunging (cervical) when mucous extravasates below the mylohyoid muscle extending along the fascial planes of the neck. The prevalence of plunging ranulas is unknown, but they are considered uncommon. (ISRN Dent. 2011;2011:806928; https://bit.ly/2ziH5M6.)
Ranulas are usually large, unilateral, translucent, bluish swellings lateral to the midline in the floor of the mouth. They often present as painless swelling with rapid onset and fluctuate in size. Plunging ranulas can present as neck masses when they extend below the mylohyoid muscle into the soft tissue of the neck. There may be a recent or remote history of trauma (oral surgery) to the mouth or face. The pseudocysts usually last for three to six weeks. Infections are uncommon, so pain, tenderness, fever, and adenopathy are rarely seen. Large ranulas can interfere with speech, chewing, and swallowing.
Differentials of cystic swelling of the floor of the mouth should include abscess, lipoma, benign or malignant salivary gland neoplasm, hemangioma, lymphangioma, fibroma, dermoid cyst, venous lake, sialolithiasis, or Ludwig's angina. (Paediatr Child Health. 2006;11:107; https://bit.ly/2Y1K3yP.)
The diagnosis is often based on appearance and location. Ultrasound is a noninvasive, safe, and inexpensive procedure to diagnose a simple ranula. (J Med Imaging Radiat Oncol. 2008;52:101; West J Emerg Med. 2016;17:827; https://bit.ly/2S44MhN.). A high-resolution ultrasound can also detect simple cysts, calculi, abscess, and often benign versus malignant tumors. CT is seldom needed for diagnosing simple ranulas, but can define the extent and origin of the lesions. A CT scan with IV contrast of the neck can be helpful to exclude other diagnoses for plunging ranulas that extend into the lateral aspect of the neck.
The most effective treatment involves intraoral surgical excision of the affected major salivary gland. (Am J Otolaryngol. 2020:102418.) Complete excision of the pseudocyst is not necessary because ranulas lack a true epithelialized cyst wall. Excision of the affected salivary gland was 99 percent successful in one study, while excision of the pseudocyst alone or marsupialization of the pseudocyst was only 63 percent or 55 percent successful, respectively. (Head Neck. 2010;32:1310.)
Nonsurgical treatment with sclerotherapy using OK-432 (picibanil) has been successful in treating intraoral and plunging ranulas in case series from Korea and Japan. (AJNR Am J Neuroradiol. 2006;27:1090; https://bit.ly/2xUtPNl.) The treatment, however, is not available in the United States.
This patient presented to the emergency department with a possible airway obstruction due to the severity of the sublingual swelling. She showed no other signs of an acute allergic reaction or a facial cellulitis, and received dexamethasone, ampicillin-sulbactam, and intravenous fluids. A CT of her neck showed a large cystic structure in the left sublingual space extending into the submandibular space, consistent with a plunging ranula.
Otolaryngology performed a bedside flexible fiberoptic nasopharyngolaryngoscopy. She had mobile vocal folds and moderate posterior displacement of the tongue, but it was nonobstructive, and she had no posterior pharynx edema or erythema. Needle drainage was then performed on the cystic structure, and 30 mL of salivary and serous fluid was removed. Cultures were sent and ultimately showed no growth.
Her symptoms improved after drainage, and she was observed for re-accumulation. She was discharged with a seven-day course of amoxicillin-clavulanic acid, and followed up in the otolaryngology clinic, where needle aspiration of the sublingual fluid collection was performed again for her comfort. She was scheduled for a transoral excision of the lesion with a left sublingual gland removal three days after. Her postoperative course was uncomplicated.
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Dr. Selbyis an assistant professor of emergency medicine at The Ohio State University School of Medicine at Wexner Medical Center. Follower her on Twitter@DocSelbs. Read her past columns athttp://bit.ly/EMN-QuickConsult.