Case Report: Misdiagnosed cystic lymphangioma presenting as recurrent submandibular cellulitis: diagnostic and therapeutic pitfalls

Introduction

Cystic masses in the submandibular region present a diagnostic challenge due to their diverse etiologies, which may be congenital, inflammatory, or neoplastic. Among these, cystic lymphangioma is a rare benign lymphatic malformation that occurs predominantly in children, with fewer than 10% of cases diagnosed in adults.^1,2 Its clinical presentation can be misleading, often leading to misdiagnosis and repeated ineffective treatments. We present a unique case characterized by a presentation of adult-onset, an initial misdiagnosis as a branchial cyst and later as sialadenitis, recurrent infections despite multiple interventions, and the eventual need for a two-stage combined surgical approach that includes endoscopic and open resection. The purpose of this work was to highlight the diagnostic difficulties associated with submandibular cystic masses and to discuss the therapeutic challenges in the management of cystic lymphangiomas, particularly in cases of recurrence and multiple surgical interventions.

Case presentation

A 55-year-old male patient with no significant medical history presented multiple recurrent episodes of right submandibular cellulitis, which required several hospital admissions. Each episode was treated with antibiotics and surgical drainage. Imaging performed during a symptom-free period revealed a cystic lesion medial to the right submandibular gland.

The patient underwent a cervicotomy with complete excision of the mass. Histopathological examination identified the lesion as a branchial cyst.

Despite surgery, swelling recurred regularly. Given the patient’s history of salivary colic, sialadenitis with lithiasis was suspected. Ultrasound examination showed inflammation of the submandibular gland with dilated ducts, but no evidence of lithiasis, consistent with inflammatory stasis rather than obstructive sialolithiasis.

Subsequently, the patient underwent a right submandibulectomy. Histological analysis revealed mild submandibular sialadenitis without evidence of lithiasis. Inflammatory episodes with new collections persisted ( Figure 1), indicating an unresolved underlying condition or a complication of submandibulectomy (sialocele).

Figure 1. Coronal (A,B) and Axial CT (C,D) scan of the neck showing features of right cervical cellulitis complicating the superinfection of a cystic lesion involving the right submandibular and sublingual spaces.

In recent admission, laboratory tests showed a marked elevation of C-reactive protein (80 mg/L), consistent with active inflammation.

Cervicofacial magnetic resonance imaging ( Figure 2) revealed a multiloculated cystic lesion measuring 69 × 26 mm, which extended into the sublingual region, suggestive of a cystic lymphangioma of the submandibular space.

Figure 2. Coronal (A,B) and Axial (C,D) MRI T2 et T2 showing a multilobulated cystic submandibular lesion with thin internal septations and peripheral enhancement, in contact with the right sublingual gland. The appearance is suggestive of a cystic lymphangioma or a cyst arising from accessory salivary glands.

The patient underwent surgery. Intraoperatively, a cyst was identified in the vallecula and resected by an endoscopic approach using a laser. The multiloculated cystic mass in the submandibular region was completely resected by reopening the previous submandibulectomy incision. Histopathological analysis confirmed the diagnosis of cystic lymphangioma with clear resection margins. Postoperative recovery was uneventful. At 1-year follow-up, the patient showed no signs of tumor recurrence ( Figure 3) or other inflammatory episodes, which confirmed the success and durability of treatment.

Figure 3. Postoperative appearance showing absence of swelling and regression of inflammatory signs, except for the surgical scar.

Discussion

Cystic lesions of the submandibular region in adults remain diagnostically challenging due to their rarity and broad differential diagnoses, including branchial cleft cysts, mucoceles, sialadenitis, sialolithiasis, neoplasms, and even schwannomas.³ In the context of recurrence, as in our case, these challenges are compounded by previous surgical alterations, leading to overlapping imaging and clinical features with postoperative changes such as fibrosis, pseudocysts, or seromas.

Accurate diagnosis is highly dependent on imaging, particularly high-resolution MRI, which remains the modality of choice. It allows a detailed characterization of the lesion content, assessment of anatomical extent, and relationships with adjacent structures. In our patient, magnetic resonance imaging revealed a multiloculated cystic lesion suggestive of a lymphatic malformation, initially misinterpreted as a branchial cleft cyst. Serial imaging was crucial in differentiating persistent pathology from postoperative sequelae.⁴

Cystic lymphangiomas are nonencapsulated infiltrative lesions that can extend between fascial planes and surround neurovascular structures. This makes complete surgical excision difficult, particularly in recurrent cases. As in our case, distorted anatomy from previous interventions further complicates both radiological, histologic evaluation, and operative management. The initial histopathological diagnosis of a branchial cyst was probably confounded by overlapping features with cystic lymphangiomas, as both can present cystic spaces lined by endothelial or epithelial-like cells. In addition, repeated episodes of inflammation and fibrosis may have altered the typical histological pattern, making a definitive diagnosis difficult without adjunct immunohistochemical studies.

Fine needle aspiration (FNA) can help rule out malignancy, though in lymphangiomas, the aspirated fluid is typically acellular and protein rich. However, FNA should always be interpreted with caution, especially in recurrent lesions.⁵

Given the proximity of vital nerves such as the marginal mandibular, lingual, and hypoglossal, any diagnostic or therapeutic intervention must minimize iatrogenic injury. Surgical planning must incorporate strategies such as intraoperative nerve monitoring and meticulous dissection, particularly in reoperative fields.⁶

Recurrent lymphangiomas management strategies should be multidisciplinary and individualized. Although surgery remains the mainstay of localized symptomatic disease, it is not always curative. The aim, particularly in recurrence, often shifts toward maximal safe debulking rather than complete excision. Adjunctive therapies such as sclerotherapy, especially for macrocystic forms, and sirolimus for more extensive or microcystic disease, have shown promising results and should be considered, particularly when surgery poses significant risks.^7,8

In our patient, complete surgical excision was achieved, including resection of an associated vallecular cyst by endoscopic laser. The postoperative course was favorable and at one-year follow-up, no recurrence was observed, supporting the success of definitive surgical treatment when feasible. Regarding sclerotherapy, although it is an effective minimally invasive treatment for macrocystic or mixed lymphatic malformations, it was not chosen in this case due to the multiloculated and infiltrative nature of the lesion, involving critical anatomical regions that presented challenges for complete access and effective delivery of sclerosing agents.

Conclusion

Recurrent cystic lymphangiomas of the submandibular region present diagnostic and therapeutic challenges due to their infiltrative nature, mimicry of other entities, and anatomical complexity. Magnetic resonance imaging plays a pivotal role in guiding diagnosis and management. As illustrated in our case, when complete resection is possible and performed with the appropriate surgical precautions, long-term outcomes are favorable. Although sclerotherapy is generally preferred for macrocystic or mixed forms, surgical excision remains essential in complex recurrent cases. A multidisciplinary approach remains essential to optimize both disease control and functional preservation. Early recognition and multidisciplinary management are crucial to improve outcomes and preserve function.

Informed consent/Patient consent

Written Informed Consent from the patient for the publication of this case report was obtained.

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