Cysts Flashcards
What is the difference between a cyst and a pseudocyst?
Cyst = epithelial lining
Pseudocyst = No lining
What are the histological features of a Epidermoid Cyst?
Cyst filled with laminated Keratin
Stratified squamous epithelium with a granular layer
+/- inflammatory infiltrate if ruptured
What conditions may cause multiple epidermoid cysts?
Gardners syndrome (Familial adenomatous papulosis)
Basal call navues syndrome
Acne Vulgaris
What is a Dilated Pore of Winer?
A single dilated pore, often on the face of adults.
What are the histological features of a dilated pore of Winer?
Stratified squamous epithelium with a granular layer
Dilated follicular opening
Keratin debris
Finger like projections of the lining
What is the histology of Milia?
Same as epidermoid Cyst
Stratified squamous epithelium with a granular layer
Laminated keratin
What is Milia en Plaque?
Multiple grouped Milia on an erythematous plaque
Rx options for Milia
Incision and expression
Laser Ablation
Electrocautery
Topical retinoid if there are many
Which part of the hair follicle to epidermoid cysts arise?
The follicular infundibulum
What is the histology of a Tricholemmal cyst and how does it differ from a epidermoid cyst?
Stratified squamous epithelium
- NO granular Layer
- cells near cyst cavity are swollen and pale
Cystic cavity filled with dense eosinophilic keratin
- often with calcification
What gene is ass with Trichilemmal cysts?
PLCD1 (AD inheritance)
Where do trichilemmal cysts normally occur?
The scalp, often multiple
How do you treat a trichilemmal cyst?
Excision (often pop out easily)
How does a vellus hair cyst present clinically?
Numerous dome shaped papules
Normally on the trunk
Can be skin coloured or hyper pigmented
What are the histological features of a vellus hair cyst?
Stratified squamous epithelium
Epidermoid keratinisation
Vellus hairs in the cyst cavity
What do you see on histology for a ruptured epidermoid cyst?
Fragments or absence of the epithelial lining
Neutrophilic and histolytic infiltrate
Fragments of keratin / Keratin flakes
What is a steatocystoma?
A benign cyst with squamous epithelial lining and associated sebaceous glands
How does a steatocystoma present?
single or multiple flesh coloured papules with oily contents
Tend to occur on the chest, axillae and groin
What is steatocystoma multiplex?
Autosomal Dominant condition characterised by multiple steatocystomas
Gene affected = Keratin 17 (KRT17)
What do you see on histology of a steatocystoma?
dermal cyst
lined by a thin stratified squamous epithelium
WITHOUT a granular layer.
Epithelium is surrounded by an irregular, corrugated eosinophilic cuticle
What is a follicular hybrid cyst?
Represent a histologic variant
Dermal cysts with stratified squamous lining in which there is transition in the wall between epidermoid keratinization and tricholemmal or matrical keratinization
What is a pigmented follicular cyst?
Dermal cysts
Often with a connection to the epidermis
Lined by stratified squamous epithelium with a granular layer
contains pigmented terminal hair shafts.
What is a dermoid cyst?
Benign cutaneous cyst that arises from the entrapment of ectodermal elements along the lines of embryonic closure
They contain other normal cutaneous structures such as hair, sebaceous lobules, eccrine glands, apocrine glands, and/or smooth muscle.
What precaution should be taken prior to excision of a dermoid cyst?
Imaging
the differential diagnosis includes neural heterotopias, imaging to exclude connection to the CNS
What is an ear pit?
A congenital defect
the ear is formed by the fusion of six tubercles: three each from the first two branchial arches.
Preauricular cysts reflect defective embryologic fusion with epithelial entrapment.
may present as a true cystic nodule or an invagination in the preauricular area
Unilateral,
Right sided
What is the histology of an ear pit?
epidermal-lined cyst with stratified squamous epithelium and a granular layer
List the types of cysts with stratified squamous epithelium and a granular layer?
Epidermoid cyst
Proliferating epidermoid cyst
Milia
Ear Pit
Pilonidal cyst
Vellus hair cyst
Pigmented follicular cyst
Pore of Wine
List the cysts with stratified squamous epithelium and NO granular layer
Tricholemmal cyst
Proliferating tricholemmal cyst
What is a pilonidal cyst?
inflamed, painful, cystic swelling
upper gluteal cleft or sacrococcygeal area
What is the aetiology of pilonidal cysts?
Some authors believe they are congenital, essentially representing a dermoid cyst
most authors now believe that the vast majority of lesions are acquired, representing a foreign body response to entrapped hair.
Pilonidal cysts may be seen in which clinical tetrad?
Follicular occlusion tetrad
Acne Conglobata
HS
Dissecting cellulitis
Pilonidal cyst
What is the histology of a pilonidal cyst?
Epidermal-lined cyst or sinus tract.
Cyst cavities contain hair and keratin debris and are surrounded by fibrosis, granulation tissue, and mixed inflammation.
What is a hydrocystoma?
benign cystic tumors that arise from apocrine or eccrine sweat glands.
present as translucent, skin-colored to bluish cysts on the face
What is the histology of apocrine Hidrocystoma?
unilocular to multi- locular dermal cysts l
lined by two layers of epithelial cells that show luminal bulbous protrusions (“snouting”) and decapitation secretion
What is the histology of eccrine Hidrocystoma?
uniloculate cyst containing clear fluid, lined by two layers of cuboidal to flattened epithelium
Where are Bronchogenic cysts located?
Suprasternal notch
Rarely anterior neck / chin
What is a bronchogenic cyst?
A rare congenital malformation
Arise from abnormal budding of the foregut during early embryonic development
typically occurring along the tracheobronchial tree
What is the histology of bronchogenic cyst?
pseudostratified, ciliated, columnar epithelium with interspersed goblet cells.
The cyst wall often contains smooth muscle and mucous glands and rarely cartilage.
What is a thyroglossal duct cyst?
A cyst that arises from remnants of the thyroglossal duct
Often moves with swallowing (attaches to the hyoid bone)
Lists the cysts without an epidermal lining? (4)
Mucocele
Digital mucous cyst
Ganglion
Pseudocysts (of the auricle and synovial)
What are the three main categories of cutaneous cysts?
Cysts with stratified squamous epithelial lining
Cysts with non-stratified squamous epithelial lining
Cysts without an epithelial lining
What two cysts may occur on the umbilicus?
- Omphalomesenteric duct cyst
- remnant of the omphalomesenteric duct
= fetal connection between midgut and yolk sac)
- lined by gastric mucosa - Urachal cyst
- due to incomplete closure of the urachus
= fetal bladder connection to umbilicus
- Uroepithelial lining or cuboidal or columnar cells
What is the name of cyst that commonly occurs on the ventral aspect of the penis? and why does it occur? What is the key histology finding?
Median Raphe Cyst
This is due to aberrant urethral epithelium
Stratified columnar epithelium (1 - 4 cells thick)
What is the name of the cyst that occurs on the labia majoa? and the ass histology?
Cutaneous Ciliated Cyst
Histology: Unilocular or multiloculated, lined by ciliated cuboidal/columnar epithelium with papillary projections.
Where do branchial cleft cysts occur?
Pre-auricular region, mandibular region or along the sternocleidomastoid muscle
Treatment options for hydrocystomas?
Excision (if single)
1% atropine (if multiple, recurs when stops)
Botox can flatten
