Bilateral neonatal submandibular cystic hygroma with critical airway compromise: a stepwise multimodal management approach in a resource-limited setting: a case report

Abstract

Background:

Cystic hygroma is a congenital lymphatic malformation most commonly involving the cervical region. Bilateral submandibular involvement in neonates is extremely rare and may rapidly progress to life-threatening airway obstruction due to proximity to the upper airway and the limited neonatal physiological reserve.

Case presentation:

We report a 29-day-old female neonate presenting with progressively enlarging bilateral submandibular cystic swellings associated with feeding difficulties and respiratory distress, necessitating nasogastric feeding. On examination, the infant had significant airway compromise requiring intubation. Imaging confirmed multiloculated cystic lesions causing marked compression of the upper airway without vascular invasion. Initial management involved endotracheal intubation and ultrasound-guided aspiration, leading to transient improvement. Intralesional doxycycline sclerotherapy was subsequently performed, resulting in partial regression and successful extubation. However, recurrence of respiratory distress necessitated reintubation and definitive surgical excision. Intraoperatively, prior sclerotherapy induced fibrosis, facilitating safer dissection with reduced bleeding. The postoperative course was uneventful, with full recovery.

Discussion:

This case demonstrates the importance of a structured stepwise approach to neonatal lymphatic malformations. While aspiration and sclerotherapy provide temporary stabilization, definitive surgical excision remains necessary in complex multiloculated lesions. Intralesional doxycycline may offer dual benefits by reducing cyst volume and improving surgical planes through fibrosis, supporting its adjunctive role in resource-limited settings.

Conclusion:

Early airway stabilization followed by staged sclerotherapy and timely surgical intervention is essential for optimal outcomes in neonatal cystic hygroma.

Introduction

Cystic hygroma (a congenital lymphatic malformation) is a benign developmental anomaly resulting from the failure of lymphatic channels to connect with the central lymphatic system, leading to cystic dilation. The incidence is approximately 1 in 6000 to 1 in 16 000 live births, with most cases occurring in the posterior cervical region ^[1,2^].

HIGHLIGHTS

• Bilateral submandibular cystic hygromas in neonates are extremely rare and can rapidly cause airway obstruction and feeding difficulties.

• A stepwise management approach using aspiration and intralesional doxycycline can temporarily relieve airway compromise and facilitate surgery.

• Definitive cyst enucleation ensures complete removal, improves feeding, and prevents recurrence, especially after sclerotherapy-induced cyst sclerosis.

• Successful outcomes depend on early recognition, continuous monitoring, timely intervention, and multidisciplinary coordination in resource-limited settings.

Submandibular and bilateral involvement are rare and pose a high risk of airway compromise in neonates due to the anatomical proximity of these lesions to the upper airway. Neonates are particularly vulnerable because of their narrow airway caliber, low functional residual capacity, and high oxygen demand, making even moderate lesions clinically significant^[2,3^].

Management includes observation, aspiration, sclerotherapy, and surgical excision. Doxycycline is widely used in low-resource settings due to its accessibility and effectiveness^[3,4^], although definitive surgery remains necessary in complex cases.

Case presentation

A 29-day-old female neonate was referred with progressively enlarging bilateral submandibular swellings noted since birth. The masses had steadily increased in size and were associated with worsening respiratory distress, recurrent choking episodes, and significant feeding difficulty, requiring nasogastric tube support.

The infant was born at term via spontaneous vaginal delivery with Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. There was no antenatal detection of abnormalities, and the immediate postnatal period had been uneventful until progressive neck swelling became evident.

On examination, the neonate was in moderate-to-severe respiratory distress with oxygen saturation ranging between 89% and 91% on room air, tachypnea, and intercostal retractions. Bilateral soft, fluctuant submandibular masses were noted, extending from the mandible to the hyoid region, with a clear right-sided predominance and marked distortion of the neck contour. These clinical findings were consistent with significant upper airway compromise, necessitating urgent airway and feeding support, as illustrated in Figure 1, where the neonate is seen with obvious bilateral submandibular swelling, respiratory distress, and dependence on nasogastric feeding due to an inability to maintain safe oral intake.

Figure 1.

Initial and perioperative images demonstrating bilateral, soft, cystic submandibular masses extending from the mandibular border to the hyoid bone, more prominent on the right (red and black arrows), causing respiratory compromise and feeding difficulty, and requiring enteral feeding and endotracheal intubation (blue arrows).

Initial laboratory investigations, including a full blood count and biochemical profile, were within normal limits, thereby excluding infectious or metabolic causes of swelling.

Ultrasonography of the neck demonstrated multiloculated cystic lesions with thin septations, consistent with a lymphatic malformation. Further evaluation with contrast-enhanced computed tomography confirmed submandibular cystic masses occupying both submandibular spaces, with a significant mass effect causing compression and displacement of the upper airway, without vascular invasion or thoracic extension. These radiological findings, shown in Figure 2, clearly demonstrated the anatomical relationship between the multiloculated lesions and the compromised upper airway, explaining the severity of respiratory symptoms.

Figure 2.

A contrast-enhanced CT scan shows multiple submandibular cystic lesions (blue arrows) that compress the upper airway (black arrows), with no evidence of vascular invasion or intrathoracic extension, and clearly delineates the lesion boundaries and their mass effect on adjacent upper airway structures.

Due to progressive respiratory deterioration, urgent endotracheal intubation was performed, resulting in immediate stabilization of oxygen saturation and relief of airway obstruction. Following stabilization, ultrasound-guided aspiration of the cystic lesions was carried out, yielding clear lymphatic fluid and producing a temporary reduction in swelling with improved airway patency. However, gradual reaccumulation of cystic fluid occurred during the following days, reflecting the persistent nature of the lesion.

Given the recurrent and progressive nature of the malformation, and with the intention of avoiding surgery in a critically ill neonate, intralesional doxycycline sclerotherapy was performed on day 10, after aspiration of the cyst contents. A total of 10 mL of a 1:1 mixture of doxycycline and normal saline was instilled into the dominant lesion under sterile conditions. Serial clinical assessments and bedside ultrasonographic examinations over the ensuing days demonstrated a progressive reduction in cyst volume, with partial collapse of several loculi and improved airway patency. Within 72 hours, there was a marked reduction in cyst volume with improved respiratory effort, allowing successful extubation on day 13. The response to sclerotherapy is demonstrated in Figure 3A, where partial collapse of the treated cyst and increased wall firmness are evident, correlating with clinical improvement and successful weaning from ventilatory support.

Figure 3.

(A) Image showing post-aspiration management with intralesional doxycycline therapy, which provided temporary relief of airway compression, allowing extubation. Ten milliliters of a 1:1 mixture of normal saline and doxycycline were injected into the right-sided cystic lesion, partially reducing its volume and inducing hardening (blue arrow), facilitating subsequent surgical manipulation. (B) and (C) Intraoperative images showing the right-sided cyst, previously treated with sclerotherapy, exhibiting marked hardening (black arrow). The hardened portion of the lesion was carefully dissected and completely enucleated during surgery (blue arrow). (D) and (E) Intraoperative images illustrating preservation of the surrounding neurovascular structures (black arrow). The procedure was completed uneventfully, with meticulous hemostasis achieved and confirmed at the operative site (blue arrow).

Because doxycycline-induced sclerosis may continue to exert therapeutic effects over several days and the patient demonstrated favorable clinical and radiological improvement, close observation was continued to maximize the benefit of minimally invasive treatment and potentially avoid surgery. However, despite this initial response, the neonate developed sudden acute respiratory distress on day 15 after aspiration, necessitating reintubation. Repeat ultrasonography demonstrated re-expansion of the multiloculated cystic lesion with recurrent upper airway compression. These findings indicated failure of conservative and minimally invasive management and prompted a multidisciplinary discussion involving pediatric surgeons, neonatologists, anesthesiologists, and radiologists, leading to the decision to proceed with definitive surgical management.

Surgical exploration was performed via a transverse cervical incision with careful elevation of subplatysmal flaps. Intraoperatively, multiple multiloculated cystic lesions were identified bilaterally. Notably, the previously sclerosed right-sided lesion demonstrated marked fibrosis and wall thickening, which significantly facilitated surgical dissection by providing clearer tissue planes and reducing intraoperative bleeding. This intraoperative advantage is illustrated in Figure 3B and C, where the sclerosed cyst shows dense fibrotic transformation compared with the contralateral lesion, allowing safer separation from surrounding vital structures.

Complete enucleation of bilateral cystic lesions was achieved with meticulous preservation of the marginal mandibular branch of the facial nerve, the hypoglossal nerve, and adjacent vascular structures. Figure 3D and E demonstrates the final surgical outcome, showing complete excision of both lesions with intact neurovascular structures and satisfactory hemostasis.

The postoperative course was uneventful. The neonate was extubated after 72 hours with stable oxygen saturation ranging between 98% and 100%. Feeding was gradually reintroduced from nasogastric feeding to full oral intake without difficulty. The patient was subsequently discharged in stable condition with a well-healed surgical wound and no residual neck swelling.

Discussion

Cystic hygroma is a congenital lymphatic malformation with a variable presentation, ranging from asymptomatic lesions to severe airway compromise^[1,5^]. Bilateral submandibular involvement is extremely rare and poses significant clinical challenges due to its proximity to the airway and the risk of rapid progression^[5,6^].

Neonates are particularly vulnerable due to their narrow airway diameter and limited respiratory reserve^[2,3^]. Early airway protection is therefore critical.

Aspiration provides only temporary relief because persistent lymphatic channels predispose to fluid reaccumulation. Sclerotherapy, particularly with doxycycline, induces inflammatory fibrosis and cyst collapse^[3,4^]. In our patient, aspiration and subsequent intralesional doxycycline were initially selected to achieve airway stabilization and potentially avoid surgery in a young neonate. Serial clinical and ultrasonographic assessments demonstrated partial collapse of the cystic spaces with improvement in airway patency, which allowed successful extubation and justified continued observation. Because the therapeutic effects of doxycycline-induced fibrosis are often delayed, a period of close monitoring was considered appropriate to maximize response before proceeding to surgery.

In this case, doxycycline provided both a therapeutic reduction and an intraoperative benefit by inducing fibrosis that improved surgical dissection. Similar findings have been reported in the literature, where preoperative sclerotherapy reduces intraoperative bleeding and improves surgical safety^[7,8^]. However, despite the initial favorable response, recurrence of respiratory distress associated with radiological evidence of lesion re-expansion indicated the failure of minimally invasive treatment. Given the recurrent life-threatening airway compromise and the multiloculated nature of the lesion, definitive surgical excision was considered unavoidable. Similar observations have been reported in complex lymphatic malformations, where multiloculated lesions frequently show an incomplete response to sclerotherapy and ultimately require surgery^[9^].

This case highlights the importance of a structured, stepwise approach combining airway stabilization, serial imaging surveillance, sclerotherapy, and timely surgical intervention, particularly in resource-limited settings. Dynamic integration of radiological findings with evolving clinical status is essential for determining the optimal timing of definitive surgery in airway-threatening neonatal lymphatic malformations.

Conclusion

Bilateral neonatal submandibular cystic hygromas are rare and potentially life-threatening conditions. A structured, stepwise approach involving airway stabilization, sclerotherapy, and definitive surgical excision is essential.

Intralesional doxycycline may provide both therapeutic and surgical advantages. Early escalation to surgery is crucial in recurrent or airway-compromised cases.

Ethical approval

Ethical clearance was not necessary for a single case report.

Consent

Written informed consent was obtained from the parents for publication of this case report and the accompanying images. A copy of the written consent is available for review by the corresponding author of this journal.

Sources of Funding

No funding was required to publish this case.

Author contributions

M.S. and H.K. contributed equally to this work and share correspondence responsibility. M.S.: Conceptualization, data curation, writing the original draft and submission. H.K.: Patient management, data acquisition, clinical review of the manuscript. N.K.: Patient management, methodology and literature review, revised the article. A.M.: Imaging interpretation, diagnosis support, revised the article. P.J.L.: Oral and maxillofacial surgeon, supervision, revised the article. A.M.M.: Oral and maxillofacial surgeon, supervision, approved the article.

Conflicts of interest disclosure

All authors declare that there are no conflicts of interest.

Research registration unique identifying number (UIN)

Not registered.

Guarantor

All authors in the article accept full responsibility for the work, have access to the patient’s information, and decide to publish.

Provenance and peer review

Not commissioned, externally peer reviewed.

Data availability statement

The datasets used in the present study are available from the corresponding author upon request.

AI statement

This confirms that no AI tools were used in manuscript preparation.

SCARE guideline

The work has been reported in line with the SCARE criteria[10].