Benign tumours Flashcards
What is a sebaceous cyst?
Refers to epidermoid and pilar cysts.
What is an epidermoid cyst?
Benign cyst that is made of a thin layer of squamous epithelium and originating in the epidermis. It contains keratin, NOT sebum (as such, ‘sebaceous’ cyst is a misleading term).
What is a pilar cyst?
AKA Trichilemmal cyst. Benign cyst that is made of a thin layer of squamous epithelium and originating from hair follicles. It contains keratin, NOT sebum.
What is the pathophysiology of sebaceous cysts?
Lined by squamous epithelium without a granular layer (just outermost stratum corneum), cysts are filled with ‘wet’ keratin.
What is the aetiology of epidermoid cysts? (x4)
- Implantation of the epidermis into the dermis such as in trauma or surgery
- Gardner’s syndrome
- Nevoid basal-cell carcinoma syndrome
- High levels of testosterone and androgenic anabolic steroids
What is the aetiology of pilar cysts?
Hereditary – autosomal dominant.
What is the epidemiology of pilar cysts: Gender?
Pilar cysts more common in females.
What are the signs and symptoms of epidermoid cysts? Where?
- Parts of body where there is little hair
- Smooth, mobile, tense lump
- Contains fibrous tissue and fatty, keratinous substance that resemble cottage cheese (has characteristic cheesy smell)
What are the signs and symptoms of pilar cysts? Where?
- Parts of body where there is a lot of hair (lots of follicles from which they originate) – most often on the scalp, but also face and neck
- Multiple usually appear at once
- Smooth, mobile, hard lump
- Contains fibrous tissue and fatty, keratinous substance that resemble cottage cheese (has characteristic cheesy smell)
- May be associated with overlying hair loss
What are the investigations for sebaceous cysts?
Clinical suspicion. EXCISIONAL BIOPSY: microscopy shows it is lined by stratum corneum (cornified epithelium) containing keratin without calcifications.
What is lipoma?
Slow-growing, benign tumours composed of adipose tissue.
What is the aetiology of lipomas? (x5)
- Mostly idiopathic
- Hereditary e.g., familial multiple lipomatosis and Gardner’s syndrome.
- Trauma
- Madelung’s disease: lipomas on head, neck and shoulders, associated with men and alcohol
- Dercum’s disease: painful lipomas on trunk, shoulders arms, associated with middle-aged women
What is the pathophysiology of lipomas?
Lobulated lesions composed of adipocytes and surrounded by thin, fibrous capsule. They are slow growing. They are mostly found cutaneously in the subcutaneous tissue, but can also be found in the GI tract (in the submucosa), adrenal glands, parotids, and breast.
What are the different types of lipoma? (x6)
• SUPERFICIAL SUBCUTANEOUS: most common • ANGIOLIPOMAS: adipocytes interspersed with capillaries containing fibrin thrombi. • SPINDLE CELL: contains adipocytes and collagen-forming spindle cells that replace adipocytes • INTRAMUSCULAR: poorly circumscribed and infiltrative (unlike usual lipomas) • HIBERNOMAS: contain brown adipocytes • LIPOBLASTOMA: brown fat tumour found in children under three
What is the epidemiology of lipomas: Age?
Develop most commonly between 40 and 60 years.
