What is the significance of a mobile lump in the suprasternal notch?

Significance of a Mobile Lump in the Suprasternal Notch

A mobile lump in the suprasternal notch most commonly represents a benign lesion such as a dermoid cyst, but requires proper imaging evaluation to rule out malignancy, especially if the mass has persisted for more than 2-3 weeks.

Clinical Evaluation

Initial Assessment

• A thorough history should assess duration of the mass, associated symptoms (voice changes, swallowing difficulties, pain), and risk factors for malignancy 1
• Physical examination should include visualization of the larynx, base of tongue, and pharynx if the mass is deemed at increased risk for malignancy 1
• Key warning signs that increase risk for malignancy include:
  • Mass persisting longer than 2-3 weeks
  • Voice changes
  • Trouble or pain with swallowing
  • Unexplained weight loss
  • Fever >101°F 1

Differential Diagnosis

• Benign etiologies (most common):
  • Dermoid cyst - congenital and typically benign 2, 3
  • Lipoma - benign tumor composed of mature adipocytes 4
  • Thyroglossal duct cyst
  • Lymph node enlargement due to infection 5
• Malignant etiologies (less common):
  • Metastatic lymphadenopathy
  • Thyroid malignancy extending to suprasternal region 5
  • Lymphoma

Diagnostic Approach

Imaging Studies

• Ultrasound is the recommended first-line imaging modality for evaluation of a suprasternal mass 1, 4

  • For dermoid cysts: may show a cyst filled with uniform nodules of fat density (pathognomonic "sack of marbles" sign) 2
  • For lipomas: typically appear as hyperechoic, well-circumscribed masses with minimal to no internal vascularity on Doppler examination 4

• CT scan may be indicated if:

  • Ultrasound findings are inconclusive
  • There is suspicion of malignancy
  • Evaluation of deeper structures is needed 1, 6

• MRI may be considered for better soft tissue characterization when ultrasound and CT are inconclusive 6

Tissue Sampling

• If imaging suggests a benign entity with definitive characteristics (e.g., simple cyst, lipoma with classic features), clinical follow-up may be appropriate 1
• Image-guided core biopsy is preferred over fine-needle aspiration for tissue sampling when diagnosis remains uncertain 1
• For palpable masses with probably benign features on imaging, short-interval follow-up is a reasonable alternative to immediate biopsy 1

Management Considerations

For Benign-Appearing Lesions

• If a benign entity has been definitively identified on imaging, clinical follow-up is appropriate 1
• For dermoid cysts, which are the most commonly reported lesions in the suprasternal notch, surgical excision is typically recommended even when benign due to potential for growth and cosmetic concerns 7, 3

For Suspicious Lesions

• Prompt referral to a specialist (otolaryngologist, head and neck surgeon) is warranted for masses with concerning features 1
• Complete surgical excision is typically recommended for definitive diagnosis and treatment 7, 6

Clinical Pearls and Pitfalls

Pearls

• Dermoid cysts in the suprasternal notch are rare but well-documented, especially in adults 7, 2
• The midline location is characteristic for congenital masses such as dermoid cysts 3, 6
• Most mobile masses in this location with benign imaging characteristics are likely to be non-malignant 1

Pitfalls

• Tuberculous granuloma can mimic thyroid tumors in the suprasternal region and should be considered in the differential diagnosis when inflammatory markers are elevated 5
• Physical examination alone is insufficient for diagnosis, as it correctly identifies only about 85% of soft tissue masses 4
• Even benign-appearing lesions may require excision if they cause symptoms or for definitive diagnosis 7