Abstract
A 1-week-old female infant presented with a transilluminating neck lump that increased in size with crying. The presumptive diagnosis was lymphatic malformation, but imaging raised the possibility of an abscess or necrotic tumour. A biopsy revealed a likely developmental cyst with local inflammatory change. Microlaryngoscopy revealed a fourth branchial pouch sinus, which was cauterised. The sinus and neck lump resolved without need for further treatment.
Keywords: ear, nose and throat/otolaryngology, congenital disorders, head and neck surgery, otolaryngology / ENT
Background
The differential diagnosis of a congenital neck lump includes developmental anomalies, of which there are a broad range, and, less frequently, neoplasms.1 Diagnosis of such lumps is usually clinical, and is frequently supported by imaging. Rarely, incisional or excisional biopsy is required to reach a definitive diagnosis.2
We present an unusual case of a congenital neck lump caused by a fourth branchial pouch anomaly. This is a rare, but important, differential diagnosis as it causes recurrent abscess formation despite antibiotic therapy, or indeed excision of the lesion. Misdiagnosis of fourth branchial pouch anomalies is common, with many being treated as abscesses requiring repeated incision and drainage. The mean time between onset of symptoms and ultimate correct diagnosis is reported as 5 years.2 Fourth branchial pouch anomalies are rare and represent around 2% of all branchial anomalies.3
Case presentation
A 1-week-old female infant, born at 41 weeks’ gestation following an unremarkable pregnancy with normal antenatal scans and delivery, presented with a left-sided neck lump which had been present since birth. The lump was noted to increase in size on crying and could be transilluminated. The baby was otherwise well, although had some feeding difficulties consistent with gastro-oesophageal reflux.
Investigations
An ultrasound identified a cystic mass on the left of the neck containing debris. A chest radiograph was rotated but was thought to show a displaced trachea.
Following referral to a children’s hospital, a clinical diagnosis of lymphatic malformation with possible mediastinal involvement was made. An MRI revealed a fluid-filled lesion measuring 32 mm by 25 mm by 36 mm abutting the superior border of the thymus and splaying the left common carotid artery and left internal jugular vein, which was deviated laterally. The trachea was deviated towards the right, and the oesophagus was compressed by the lesion (see figure 1). This was most consistent with a pus-filled abscess, representing a de novo infection of a congenital lesion.
Figure 1.
T1-weighted coronal MRI of the head and neck, showing a left-sided fluid filled lesion of the neck, abutting the thymus and splaying the left common carotid artery and jugular vein.
A repeat ultrasound scan showed increasing echogenicity and heterogeneity of the mass, and it was thought unlikely to be a lymphovenous malformation. The main differentials were a necrotic tumour or abscess.
The child was referred to the oncology multidisciplinary team meeting, who arranged a biopsy of the lesion, which showed inflamed stromal and lymphoid tissue, with no organ-specific histology or atypical cells. Culture of the biopsy grew Streptococcus pneumoniae and Staphylococcus aureus.
Differential diagnosis
In view of the clinical history, imaging and microscopic findings, the most likely clinical correlate was deemed to be a developmental left neck cyst with an acute inflammatory response. The bacterial culture suggested a lesion continuous with the laryngopharynx.
A microlaryngoscopy identified the ultimate diagnosis of a left fourth branchial sinus in the piriform fossa (see figure 2). Milk was able to be expressed through the sinus with pressure (see figure 3).
Figure 2.
Entrance to a fourth branchial sinus, visualised on microlaryngoscopy.
Figure 3.
Milk expressed through the fourth branchial sinus on pressure.
Treatment
15 W monopolar diathermy was applied to the tract (see figure 4). A postoperative fever was treated with systemic antibiotics.
Figure 4.
The fourth branchial sinus following endoscopic cauterisation.
Outcome and follow-up
A repeat microlaryngoscopy performed 3 months subsequently revealed that the sinus had resolved. She has been well since, with no evidence of recurrence of her neck mass.
Discussion
Branchial anomalies, such as cysts, fistulae and sinuses occur following failure of the involution of branchial, or pharyngeal, clefts and pouches. Branchial clefts and pouches form during the fourth week of embryonic development on the ectodermal or endodermal surface, respectively between the pharyngeal arches.4 The superior parathyroid glands derive from the fourth pharyngeal pouch, and thus congenital sinuses tend to lie in the vicinity of the thyroid.2
Fourth branchial pouch sinuses are rare, with a little over 100 cases described in the literature. Complete fistulae are extremely rare, although cases have been reported.5 Fourth branchial sinuses can present in a variety of different ways and at a range of ages from the neonatal period to adulthood. Neonates can present with asymptomatic masses, as with our case, or which can lead to tracheal compression and stridor.6 Around 9% of fourth branchial pouch anomalies present in the neonatal period.7
In older children and adults, fourth branchial pouch anomalies may present as recurrent upper respiratory tract infections, recurrent acute suppurative thyroiditis, cervical or thyroid pain, neck masses, or more rarely, with abscesses, cellulitis, dysphagia/odynophagia or voice changes.8 Although extremely rare, abscesses within branchial cleft or pouch anomalies can be fatal.9
The rarity of such lesions, along with the variable presentation, can make fourth branchial pouch anomalies difficult to diagnose. Although ultrasound, barium swallow and CT can be beneficial in a diagnostic work-up,2 most definitive diagnoses are made following examination of the anomaly in the operating theatre.10 The mean time between onset of symptoms and diagnosis of a fourth branchial pouch anomaly has been reported to be 5 years.2
Management of fourth branchial pouch anomalies historically involved surgical excision of the entire tract. This is extensive surgery with risks associated with the structures that the complex course of the tract runs in close proximity to—including the vagus nerve, carotid artery and oesophagus.8 Endoscopic management with diathermy causes fibrosis over the entry to the tract, effectively sealing it off and preventing further problems, and has become the standard of care due to its less invasive nature.4
Learning points.
Fourth branchial pouch anomalies are a rare but important cause of neck lumps.
They classically present as recurrent thyroiditis, but may present with asymptomatic neck lumps, respiratory distress and repeated upper respiratory tract infections.
Although imaging cane be useful in work-up, diagnosis is made by examination of the anomaly under anaesthetic.
Cauterisation has become the standard management for these anomalies.
Footnotes
Twitter: @HariboDoctor
Contributors: JR wrote the paper and performed a search of relevant literature. RN and BH were involved in the management of the patient and reviewed the article prior to submission.
Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests: None declared.
Patient consent for publication: Parental/guardian consent obtained.
Provenance and peer review: Not commissioned; externally peer reviewed.
References
- 1.Quintanilla-Dieck L, Penn EB. Congenital neck masses. Clin Perinatol 2018;45:769–85. 10.1016/j.clp.2018.07.012 [DOI] [PubMed] [Google Scholar]
- 2.Stadler TM, Morand GB, Schmid S, et al. Congenital fistula of the fourth branchial arch: report of case with long-lasting misdiagnosis. Clin Case Rep 2019;7:295–8. 10.1002/ccr3.1965 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Choi SS, Zalzal GH. Branchial anomalies: a review of 52 cases. Laryngoscope 1995;105:909–13. 10.1288/00005537-199509000-00007 [DOI] [PubMed] [Google Scholar]
- 4.Bajaj Y, Ifeacho S, Tweedie D, et al. Branchial anomalies in children. Int J Pediatr Otorhinolaryngol 2011;75:1020–3. 10.1016/j.ijporl.2011.05.008 [DOI] [PubMed] [Google Scholar]
- 5.Patel A, Hinni M. The fourth branchial complex anomaly: a rare clinical entity. Case Rep Otolaryngol 2011;958652. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Sharma HS, Razif A, Hamzah M, et al. Fourth branchial pouch cyst: an unusual cause of neonatal stridor. Int J Pediatr Otorhinolaryngol 1996;38:155–61. 10.1016/S0165-5876(96)01424-3 [DOI] [PubMed] [Google Scholar]
- 7.Yoo T, Kim S, Kim H, et al. Fourth branchial anomaly presenting with a lateral mass in a neonate. J Neonatal Surg 2014;3:34. [PMC free article] [PubMed] [Google Scholar]
- 8.Liberman M, Kay S, Emil S, et al. Ten years of experience with third and fourth branchial remnants. J Pediatr Surg 2002;37:685–90. 10.1053/jpsu.2002.32253 [DOI] [PubMed] [Google Scholar]
- 9.Tong F, Liang Y, Khan MF, et al. A fatal case of severe neck abscess due to a third branchial cleft fistula: morphologic and immunohistochemical analyses. Diagn Pathol 2016;11:87 10.1186/s13000-016-0540-0 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Shrime M, Kacker A, Bent J, et al. Fourth branchial complex anomalies: a case series. Int J Pediatr Otorhinolaryngol 2003;67:1227–33. 10.1016/j.ijporl.2003.07.015 [DOI] [PubMed] [Google Scholar]