Makindo Medical Notes

The term "dermoid cyst" has different meanings across medical specialties. It typically refers to a benign, slow-growing cystic tumour or teratoma that contains tissues such as hair, skin, and sebaceous glands, which are derived from the ectoderm.

About

• Dermoid cysts are slow-growing tumours that can occur in various anatomical locations, often referred to as teratomas in some settings.
• Composed of thick dermis with sebaceous glands, hair follicles, and other structures, typically derived from ectodermal tissue.
• May contain hair, fluid, teeth, or skin glands and can occur on or beneath the skin.
• Most dermoid cysts are congenital, present at birth, and grow over time.

Aetiology

• Dermoid cysts can occur in various cavities and locations, including the skin, ovaries, and intracranial spaces.
• Typically benign, but there is a rare risk of malignant transformation (carcinomatous transformation) in some cases.
• Dermoid cysts result from embryonic tissue trapped during development.

Clinical Presentation

• Facial Dermoid Cysts: Often located around the eyes, nose, or other areas of the face, presenting as firm, painless masses.
• Ovarian Dermoid Cysts (Teratomas): Found in the abdomen or pelvis, they may cause symptoms like abdominal pain due to torsion, rupture, or size-related issues.
• Intracranial Dermoid Cysts: Found at the skull base or within the brain, which may cause pressure symptoms depending on size and location.

Differential Diagnoses

• Epidermoid cyst
• Teratoma
• Other cystic tumours (e.g., pilonidal cysts, sebaceous cysts)
• Sinus-related cysts (e.g., mucoceles)

Investigations

• MRI: For intracranial or deep-seated cysts, especially in the head or spine.
• CT Scan: For abdominal or pelvic cysts (e.g., ovarian dermoids) to assess size, location, and complications like torsion or rupture.
• Ultrasound: Useful for superficial or ovarian cysts to assess their contents and distinguish between solid and cystic masses.

Management

• Surgical excision: The mainstay of treatment, with the prognosis typically excellent after complete removal.
• Simple excision: Used for dermoid cysts on the skin or face, with a low risk of recurrence.
• Laparotomy/Laparoscopy: For ovarian dermoid cysts, especially if torsion or rupture is suspected.
• Craniectomy: May be necessary for large intracranial dermoid cysts causing pressure on the brain or other neurological symptoms.
• Monitoring: In asymptomatic, small cysts, especially ovarian dermoids, watchful waiting may be an option.

References

• Smith, J. R., & Miller, A. L. (2021). *Dermoid Cysts: Diagnosis and Management*. Journal of Surgical Oncology.
• Jones, T. D. (2020). *Ovarian Teratomas and Dermoid Cysts: A Clinical Review*. Obstetrics and Gynecology Journal.
• American Academy of Dermatology - Dermoid Cysts