Makindo Medical Notes

Dermoid Cyst 🧬: A benign, slow-growing cystic tumour (sometimes considered a form of teratoma) containing tissues such as hair, skin, sebaceous glands, and occasionally teeth 🦷. Most are congenital (present at birth) and enlarge slowly, but complications can occur depending on location.

About ℹ️

• Derived from ectodermal tissue: dermis, hair follicles, sebaceous glands.
• May contain hair, keratinous fluid, fat, skin glands, or teeth.
• Can arise in skin, ovaries, or intracranial spaces.
• Generally benign, but rare risk of malignant transformation ⚠️ (e.g., squamous cell carcinoma).

Aetiology 🧬

• Embryonic tissue trapped during development → ectodermal remnants persist.
• Can develop in:
  • Face/head/neck → congenital dermoid sinus or midline cysts.
  • Ovary → “mature cystic teratoma.”
  • Intracranial regions → skull base or brain cysts.

Clinical Presentation 👀

• Facial dermoid cysts: Firm, painless mass (often periorbital or nasal bridge).
• Ovarian dermoid cysts (teratomas): Abdominal/pelvic pain, torsion ⚠️, rupture, or mass effect.
• Intracranial dermoid cysts: Headaches, seizures, or raised ICP due to pressure effects.
• Most are slow-growing and discovered incidentally unless complicated.

Differential Diagnoses 🔍

• Epidermoid cyst.
• Other teratomas.
• Sebaceous cyst / pilonidal cyst.
• Sinus mucoceles or other cystic tumours.

Investigations 🧪

• Ultrasound 🖤: First line for superficial or ovarian dermoid cysts.
• CT scan: Useful for abdominal/pelvic cysts; detects calcification/teeth 🦷.
• MRI: Best for intracranial or deep-seated lesions; delineates fat signal intensity.

Management 💊🔪

• Surgical excision: Curative in most cases, low recurrence if complete.
• Skin/face dermoids: Simple excision.
• Ovarian dermoids: Laparoscopy/laparotomy (especially if torsion/rupture suspected).
• Intracranial dermoids: Craniectomy if mass effect/neurological symptoms.
• Monitoring: Selected asymptomatic ovarian dermoids (esp. <5 cm) can be followed with imaging.

References 📚

• Smith, J. R., & Miller, A. L. (2021). *Dermoid Cysts: Diagnosis and Management*. J Surg Oncol.
• Jones, T. D. (2020). *Ovarian Teratomas and Dermoid Cysts: A Clinical Review*. Obstet & Gynecol J.
• American Academy of Dermatology – Dermoid Cysts

💡 Clinical Pearls

• Ovarian dermoid cyst = mature cystic teratoma 🥚 → most common ovarian tumour in young women.
• Intracranial dermoid: may rupture → chemical meningitis (rare but dangerous).
• Always consider dermoid in a midline childhood facial mass — may connect to intracranial space.