A case of cystic midline neck swelling

Case Report

• 20 year old male
• Swelling since 10 years
• Painless, slowly increasing in size.

No other ENT/General symptoms

• O/E: 5×3 cm, soft, cystic, non tender, fluctuant,non transilluminant & superficial to mylohyoid muscle. No movement with deglutition & tongue protrusion.
• Oral cavity: No bulge in the floor of the mouth.
• Rest of ENT examination: Normal.

  
Investigations

• Routine Blood & Urine: Normal.
• F.N.A.C: Inconclusive.

Clinical Diagnosis

• Sub Lingual Dermoid
• Thyroglossal Cyst
• Ranula

Treatment

• Excision under LA.
• External approach.
• Swelling was well encapsulated & part of the swelling was found extending deep to mylohyoid.
• No tract/attachment to hyoid.

Histopathology

• To our surprise, the HPE report was suggestive of Thyroglossal cyst.

D/D for midline neck swellings 

• Ludwig’s Angina.
• Sub mental Lymphadenitis.
• Sublingual Dermoid.
• Lipoma in the sub mental region.
• Sub hyoid bursitis.
• Thyroglossal cyst.
• Thyroid nodule on the isthmus.
• Pretracheal & prelaryngeal lymphadenitis.
• Suprasternal space swellings.
• Retrosternal goitre.
• Thymus swelling.

Sub Lingual Dermoid

• Sub Lingual Dermoid
• Sequestration dermoid, often bigerminal.
• Congenital but seen between 10-20 years.
• 7% of the Dermoids are seen in H&N of which only 6.5% are sublingual.
• Derived from the entrapment & subsequent growth of epithelial cells during the midline fusion between the 1st & 2nd branchial arches in 3rd & 4th week of embryonic life.

Sub Lingual Dermoid

• Lined by squamous epithelium with skin appendages, contains thick cheesy sebaceous material but no hair.
• D/D: Ranula,Cystic hygroma,Thyroglossal cyst & branchial cleft cyst.
• Treatment is excision by intraoral/external approach.

Thyroglossal Cyst

• Commonest congenital neck mass in children.
• A tubuloembryonic dermoid arising from thyroglossal tract/duct.
• Age:15-30 years
• 90% in the midline.10% to one side of which 95% are to left, over the thyroid cartilage.
• 60.9% are subhyoid.24.1% supra hyoid,12.9% sublingual & 2.1% are intra lingual.

Thyroglossal Cyst

• Thyroid tissue found in cyst wall in 45-60%.
• Often asymptomatic.
• Soft,cystic,fluctuation+/-transillumination
• Moves with swallowing & tongue protrusion
• Get Thyroid scan before excision.
• Sistrunk`s operation is the surgery of choice
• Chances of recurrence: 4-10%