Introduction
Tongue base lymphoid hyperplasia, also known as pseudolymphoma, is an uncommon benign entity associated with a rapid increase in the abundance of lymphocytes contained within or outside of lymph nodes.Reference Sands and Tewfik1 The aetiology is poorly understood, but a relationship with chronic irritation (e.g. reflux and poorly fitting dentures), a reactive lymphoid proliferation to an unknown antigenic stimulation, Epstein–Barr virus infection, allergy or repeated infection have all been postulated.Reference Jham, Binmadi, Scheper, Zhao, Koterwas and Kashyap2–Reference Kornblut, Paparella and Schumrick4
It tends to affect older patients (mean age of 61 years) and has a female-to-male ratio of nearly 3:1. It presents as a unilateral, painless, slow-growing mass that may be asymptomatic or cause discomfort during swallowing.Reference Jham, Binmadi, Scheper, Zhao, Koterwas and Kashyap2, Reference Gromet, Horner and Carter5 An irritating cough or globus sensation are also part of its symptomatology.
The diagnosis of a tongue base lymphoid hyperplasia is of clinical importance because it may be confused with malignant lymphoma on both clinical and histopathological examination. Other differential diagnoses include mesenchymal tumours, salivary gland neoplasms, adenomatoid hyperplasia, accessory thyroid tissue, cysts, papillomas, fibromas, abscesses and angiomas.Reference Gromet, Horner and Carter5, Reference Kolokotronis, Dimitrakopoulos and Asimaki6
We hereby describe a case where a patient diagnosed with tongue base lymphoid hyperplasia was successfully treated with radiofrequency excision and interstitial radiofrequency-induced thermotherapy.
Case report
A 53-year-old female presented initially to another hospital with globus sensation, mild dysphagia, nocturnal breathing problems and ‘hot potato voice’ dysphonia. On examination, she had a visible tongue mass, confirmed on flexible nasendoscopy to be obstructing the posterior oropharynx. Neck palpation findings were normal.
The patient underwent magnetic resonance imaging, which revealed an irregular mass at her tongue base that looked suspicious of lymphoma. An excision biopsy of the mass, conducted under general anaesthetic (performed at the other institution), revealed benign reactive lymphoid hyperplasia. She required a temporary (two-week) tracheostomy and nasogastric tube feeding after the biopsy to secure her airway.
The lesion unfortunately recurred within three months, causing diminished dimensions of the retroglossal area. The patient was referred to our department for further management.
On presentation to our department, the patient underwent a thorough clinical evaluation, which confirmed an irregular mass in the posterior oropharynx. On further questioning, she appeared to have symptoms suggestive of obstructive sleep apnoea (OSA), namely witnessed apnoeic episodes, snoring and daytime sleepiness. This prompted us to arrange a domiciliary sleep study. The sleep study showed moderate OSA, with an apnoea–hypopnoea index of 18.1 events per hour. Her body mass index (BMI) was 21.1 (Figure 1a).
Comparison of sleep studies conducted (a) before and (b) after three sessions of radiofrequency-induced thermotherapy (with right tonsillectomy and excision of lymphoid tissue from the tongue base). H = hour; Desat = desaturation; SpO2 = oxygen saturation; bpm = beats per minute; RMI = respiratory mechanics instability
The first surgical procedure at our institute (carried out on 25 January 2012) included an incisional biopsy of the tongue base mass. We performed radiofrequency-induced thermotherapy of the tongue base and right tonsil using an Olympus Celon® ProSleep Plus™ bipolar electrode (6 W per application). The procedure was straightforward, with hardly any blood loss. A second procedure was deemed necessary and accordingly arranged.
Her second operation was conducted four weeks later (on 22 February 2012). The procedure, which followed a difficult nasotracheal intubation, consisted of a right tonsillectomy, excision of lymphoid tissue from the tongue base with an Olympus Celon ProCut™ bipolar needle using a power setting of 25 W, together with further extensive radiofrequency-induced thermotherapy of her tongue base using the ProSleep Plus electrode with a power setting of 6 W.
The third surgical procedure, performed three weeks later, consisted of further radiofrequency-induced thermotherapy of the tongue base.
Whilst the tongue base biopsies continued to show reactive lymphoid hyperplasia histologically, a sample of her bone marrow revealed no abnormal features. The blood tests showed evidence of a past Epstein–Barr virus infection and were negative for human immunodeficiency virus. Polymerase chain reaction analysis of the biopsy specimen was negative for monoclonal T-cell expansion.
The patient was given proton-pump inhibitors (lansoprazole, 15 mg twice daily) after the first operation; these were to be used continuously in view of her mild reflux symptoms, and the documented relationship between reflux and tongue base lymphoid hyperplasia. In addition to this, simple analgesics (paracetamol 1 g up to four times a day as needed, diclofenac 50 mg up to three times a day as needed, and codeine 30–60 mg up to four times a day as needed), one week worth of mouthwash (10 ml Difflam® four times a day) and co-amoxiclav (625 mg three times a day) were prescribed after each procedure.
All three of the procedures were well tolerated by the patient with the need for only occasional pain relief. She was discharged home on the first post-operative day after each procedure.
Results
A post-operative sleep study, performed six weeks after the patient's third operation (on 26 April 2012), showed an apnoea–hypopnoea index of 3.8 events per hour (indicating no OSA). Her BMI had climbed to 22.3 (Figure 1b). This correlated well with the dramatic improvement in her sleep quality and reduction of snoring.
At the time of writing, the patient had been followed up in the out-patients department for 24 months. Over this time, the dyspnoea resolution has been sustained, with almost total restoration of voice quality. Serial flexible nasendoscopy procedures have revealed no evidence of recurrence of the tongue base lymphoid hyperplasia. There were no reported complications of surgery.
Discussion
The sleep study findings for this patient showed a reduction in the apnoea–hypopnoea index from 18.1 to 3.8 events per hour, despite an increased BMI. There was improved stability of her sleep pattern, with longer periods spent in one position and fewer episodes of desaturation (Figure 1b).
The patient experienced significant and continued post-operative improvements in her breathing, swallowing, quality of sleep and life in general. To date, the tongue base lymphoid hyperplasia has not grown back. She will receive further radiofrequency-induced thermotherapy to her tongue base as and when necessary, and will be followed up on a four-to-six monthly basis for at least another one-to-two years.
This patient required a two-week temporary tracheostomy at the referring hospital after excisional biopsy of the tongue base lymphoid hyperplasia. Whilst at our institution, she was discharged home on the first post-operative day after each of the three procedures, with no problems in breathing or swallowing, and needing only occasional simple analgesics.
We strongly feel that the radiofrequency treatment provided is superior to laser treatment in terms of thermal injury to tissues; in this study and a previous study conducted by the senior author, radiofrequency treatment caused minimal tissue thermal trauma.Reference Stimpson and Kotecha7
• Tongue base lymphoid hyperplasia is an uncommon benign entity associated with increased lymphocytes within or outside of lymph nodes
• It presents as a unilateral, painless, slow-growing mass that may be asymptomatic, or cause globus sensation, irritating cough or swallowing-related discomfort
• Tongue base lymphoid hyperplasia tends to affect older females and may be confused with lymphoma on clinical and histopathological examination
• Treatment of choice is surgical excision or debulking; there is no ‘gold standard’ regarding treatment modality
• Radiofrequency-induced thermotherapy can be valuable in managing tongue base lymphoid hyperplasia or similar benign lesions that compromise the airway
Further studies could include quality of life outcome evaluations of patients undergoing similar procedures, and a comparison of efficacy of different radiofrequency devices versus other operative techniques such as laser, diathermy and cold steel dissection.
Conclusion
The use of radiofrequency-induced thermotherapy is a valuable strategy for managing tongue base lymphoid hyperplasia or similar benign lesions that compromise a patient's airway. Our findings demonstrate a clear clinical improvement in the patient's symptoms, both subjectively and objectively.
From our experience, radiofrequency-induced thermo-therapy is a safe and reasonably straightforward surgical technique that is superior to laser treatment in terms of causing less tissue thermal trauma.
