Abstract
We report a very rare case of a plunging ranula extending into the parapharyngeal space, which was treated successfully with OK-432. A 27-year-old woman presented with a 4-month history of right submandibular swelling. Based on computed tomography and magnetic resonance imaging findings, we established a diagnosis of plunging ranula intruding into the parapharyngeal space. The patient was treated with an intracystic OK-432 injection that was administered under ultrasonographic guidance. At 6 weeks after the injection, computed tomography showed complete disappearance of the cystic mass. No recurrence was noted during the 10-month follow-up.
1
Introduction
A ranula is a mucus retention cyst or pseudocyst caused by leakage of mucus from the sublingual gland and generally occurs in the oral floor. A plunging ranula occurring in the submandibular space is less common. Plunging ranulas particularly localized in the parapharyngeal space are even rarer, and only 3 cases have been reported . All 3 patients were treated surgically. Hence, the first choice for therapy has generally been surgical excision of the ranula along with the sublingual gland; however, problems such as insufficient surgery, frequent recurrence, and the risk of damage to the surrounding structures, particularly nerves and blood vessels, have been reported.
Recently, the effectiveness of intracystic injection of OK-432 (Picibanil; Chugai Pharmaceutical, Co, Tokyo, Japan) in treating ranulas with minimal adverse effects has been reported. Here, we report the first case of a plunging ranula that was localized in the parapharyngeal space and successfully treated by an intracystic injection of OK-432.
2
Case report
A 27-year-old woman presented to our clinic with a swelling of the right submandibular area, which was persistent since 4 months. Physical examination revealed a diffuse soft swelling with indistinct borders in the right submandibular region, which was not palpable from the floor of the mouth. Neither redness nor tenderness was observed, and no thrill was palpable in that area. All laboratory tests including hemogram and blood biochemistry yielded normal results. Computed tomography (CT) showed a thin-walled cystic mass with the same density as water in the right submandibular and parapharyngeal regions ( Fig. 1 ). T1- and T2-weighted magnetic resonance imaging (MRI) showed low- and high-intensity areas in the same region ( Fig. 2 ). The aspirated contents from the cystic lesion were yellowish, mucinous, and rich in amylase. These findings confirmed a diagnosis of a right plunging ranula extending into the parapharyngeal space.
After our detailed explanation of the available treatments including ranula excision, marsupialization, combined ranula and sublingual gland excision, and OK-432 intracystic injection and their prognosis, the patient chose OK-432 intracystic injection. Under the guidance of submandibular ultrasonography, the cystic tumor was punctured using an 18G needle, and maximum possible amount of the mucus was aspirated. OK-432 solution (0.1 KE/mL, total 7 mL) was then injected using the same-sized needle, which was inserted inside the cyst. The patient had a mild inflammation and tenderness around the injected region and had slight fever that lasted for a few days. The plunging ranula disappeared completely at 6 weeks after the injection ( Fig. 3 ). No recurrence was observed during the 10-month postinjection period.
2
Case report
A 27-year-old woman presented to our clinic with a swelling of the right submandibular area, which was persistent since 4 months. Physical examination revealed a diffuse soft swelling with indistinct borders in the right submandibular region, which was not palpable from the floor of the mouth. Neither redness nor tenderness was observed, and no thrill was palpable in that area. All laboratory tests including hemogram and blood biochemistry yielded normal results. Computed tomography (CT) showed a thin-walled cystic mass with the same density as water in the right submandibular and parapharyngeal regions ( Fig. 1 ). T1- and T2-weighted magnetic resonance imaging (MRI) showed low- and high-intensity areas in the same region ( Fig. 2 ). The aspirated contents from the cystic lesion were yellowish, mucinous, and rich in amylase. These findings confirmed a diagnosis of a right plunging ranula extending into the parapharyngeal space.
