In an infant with a cyst‑like buccal mass, what are the likely diagnoses and the recommended evaluation and management?

Cyst-Like Buccal Masses in Infants: Diagnosis and Management

Primary Differential Diagnosis

In an infant with a cyst-like buccal mass, the most likely diagnoses include lymphatic malformations (formerly called lymphangiomas or cystic hygromas), vascular malformations, dermoid cysts, and less commonly, infantile hemangiomas with cystic degeneration. 1

Key Diagnostic Considerations by Lesion Type:

• Lymphatic malformations are congenital lesions that may become clinically apparent later in life due to progressive ectasia, and can be mistaken for infantile hemangiomas when bleeding occurs into surface vesicles 1
• These are subdivided into microcystic and macrocystic varieties based on predominant lacuna size 1
• Vascular malformations are structural anomalies present at birth that do not involute, though they may not be immediately apparent 1
• Dermoid cysts in the oral cavity, though rare (<0.01% of all oral cavity lesions), should be considered in the differential diagnosis of cystic masses in the floor of the mouth or buccal region 2, 3
• Infantile hemangiomas typically appear by 4 weeks of age and are usually solid, but can occasionally present with cystic features 1

Initial Evaluation Approach

Ultrasound with color Doppler should be performed as the first-line imaging modality to differentiate between solid and cystic lesions and characterize vascular flow patterns. 4, 5

Critical Clinical Features to Assess:

• Timing of appearance: Congenital lesions present at birth versus infantile hemangiomas appearing by 4 weeks of age 1
• Growth pattern: Vascular malformations grow proportionally with the child, while infantile hemangiomas proliferate rapidly then involute 1
• Associated symptoms: Infection (erythema, pain, fever), fluctuation in size, feeding difficulties, or respiratory symptoms 4
• Physical characteristics: Compressibility, color changes with crying or Valsalva, transillumination 1

Imaging Protocol

First-Line Imaging:

• Ultrasound with color Doppler is sufficient for evaluating superficial congenital anomalies and distinguishing cystic from solid lesions 4
• This modality involves no ionizing radiation and does not require patient immobility, making it ideal for infants 1

Advanced Imaging (When Indicated):

• MRI of the neck provides superior soft tissue characterization for deep lesions or when malignancy is suspected (though extremely rare in infants) 4
• CT with contrast is reserved for cases requiring evaluation of bone involvement or surgical planning 4

Common Diagnostic Pitfalls

A critical error is assuming all cystic masses in infants are benign without proper evaluation—lymphatic malformations and vascular malformations require different management than dermoid cysts or ranulas. 4, 3

Specific Pitfalls to Avoid:

• Misdiagnosing lymphatic malformations as infantile hemangiomas: Lymphatic malformations do not involute and may require different treatment approaches 1
• Confusing dermoid cysts with ranulas: Dermoid cysts require complete surgical excision, while ranulas may be treated with marsupialization 3
• Delaying appropriate imaging: Ultrasound should be performed promptly to guide management and prevent complications 4
• Overlooking airway compromise: Large oral cavity cysts can cause feeding and respiratory difficulties, requiring immediate intervention 6

Management Strategy

Initial Management:

• If infection is present, administer broad-spectrum antibiotics covering oral and skin flora, and consider aspiration if imaging demonstrates an abscess 4
• Postpone definitive surgical excision until any infection is resolved 4

Referral Indications:

All infants with confirmed congenital cervical or oral cystic masses should be referred to a pediatric surgeon or pediatric otolaryngologist for definitive management. 4

Definitive Treatment:

• Complete surgical excision represents the definitive treatment for dermoid cysts and most congenital cystic lesions to prevent recurrence and infectious complications 4, 3
• For lymphatic malformations, treatment depends on size, location, and symptoms—options include observation, sclerotherapy, or surgical excision 1
• Infantile hemangiomas with cystic features may require medical therapy with oral propranolol if causing functional impairment, but most do not need intervention 1

Timing of Intervention:

• Elective surgical resection should generally be delayed until after infancy when possible to allow for better surgical outcomes and lower complication rates 1
• Immediate intervention is indicated for life-threatening conditions, functional impairment (feeding, breathing), or significant pain 1, 4

Special Considerations for Specific Lesions

For Suspected Vascular Lesions:

• Vascular malformations exhibit normal endothelial cell turnover and expand as the patient grows, unlike infantile hemangiomas which proliferate then involute 1
• Growth may be influenced by trauma, infection, or hormonal changes 1

For Suspected Dermoid Cysts:

• These developmental anomalies require complete surgical excision as primary management 3, 7
• Recurrence is common if incompletely excised 3