Cysts Flashcards
1
Q
True cyst definition
A
have an epithelial lining, may be composed of stratified squamous epithelium or other forms of epithelia
2
Q
Pseudocyst definition
A
No epithelial lining at all
3
Q
Cysts with a stratified squamous epithelium
A
- Epidermoid - infundibular
- Milium, tricholemmal cysts, prolfierating tricholemmal cyst, infundibular cyst
- Vellus hair cyst, steatocystoma, cutaneous keratocyst, prigmented follicular cyst, dermoid cyst
- Verrucous cyst
- Ear pit cyst, pilonidal cyst
4
Q
Cysts with a non-stratified squamous epithelium
A
- Hidrocystoma
- Eccrine, appocrine
- Bronchogenic cyst
- Thyroglossal duct cyst
- Branchial cleft cyst
- Cutaneous ciliated cyst
- Median raphe cyst
5
Q
Cysts without an epithelium
A
- Mucocele
- Digital mucous cyst
- Ganglion
- Pseudocyst of the auricle
6
Q
Cyst anatomic origins
A
- Sebaceous duct: steatocystoma
- Follicular infundibulum: epidermoid cyst, milium, pigmented follicular cyst, vellus hair cyst
- Outer root sheath: tricholemmal cyst
7
Q
Cysts with a stratified squamous epithelium without a granular layer
A
tricholemmal cyst or proliferating trochlemmal cyst
8
Q
Epidermoid Cyst clinical
A
- Distribution: face, upper trunk, scrotal (multiple –> scrotal calcinosis via dystrophic calcification)
- Morphology: skin coloured-yellowish dermal nodules, central punctum
- Symptoms: asymptomatic, rupture –> pain
- Complications: rarely BCC or SCC development
9
Q
Epidermoid Cyst histology
A
- Stratified squamous epithelium with granular layer
- Cystic cavity structure
- Centre filled with laminated keratin, ‘cornflake’, keratinization
- Surrounding: acute or chronic granulomatous inflammation, +/- fibrosis
- Gardner: columns of pilomatricoma-like shadow cells projecting into the cyst cavity
- Verrucal:
- HPV associated
- irregular acanthosis
- HPV-60 type: intracytoplasmic inclusions and vacuolar keratinous changes, eccrine ducts sometimes in the cyst wall
- Verrucous cast type: epidermal cyst with a papillated and/or digitated lining with prominent hypergranulosis and irregular keratohyaline granules
- Cystic structure mimicking molluscum bodies
10
Q
Epidermoid Cyst Rx
A
- Simple excision
- Incision and expression of cyst contents and wall –> if you don’t remove it all, it may recur
- Best to excise when not inflamed
- Inflamed –> incision, drainage, may need abx, IL steroids
11
Q
Epidermoid cyst aetiology
A
- Most common cutaneous cyst
- Derivation: follicular infundibulum. May be primary or secondary
- Secondary causes:
- Disrupted follicular structures or traumatically implanted epithelium
- Acne vulgaris
- Medications: BRAF-inhibitors (both selective and non-selective)
- Syndromes:
- Gardner: FAP
- Basal cell naevus syndrome
- Disrupted follicular structures or traumatically implanted epithelium
12
Q
Dilated Pore of Winer - histo, ddx, rx
A
- Single dilated comedo on the face
- Histo: dilated follicular opening with keratinous debris, lined by squamous epithelium witha. granular layer. Lining is acanthotic with finger-like projections pushing into the surrounding dermis
- Ddx: pilar sheath acanthoma, trichoepithelioma, large pore BCC
- Rx: excision
13
Q
Milium aetiology
A
- Derivation: infundibulum of hair follicles or from eccrine ducts
- Aetiology: primary or secondary
- Secondary causes:
- Blistering: PCT, EBA
- Superficial ulceration from trauma or cosmetic procedures
- Steroid induced atrophy
- Follicular MF
- Chronic irritation
- Syndrome:
- oral-facial-digital syndrome type 1: X linked disorder, lethal in males. Milia in neonates with facial and skull malformations, Blaschkoid alopecia, PCKD
- Bazex-Dupre-Christol
- Rombo
- Loeys-Dietz
- Basan
- Brooke-Spiegler
14
Q
Milium clinical
A
- Distribution: face, mouth (minor salivary gland ducts or from epithelium entrapped within embryologic fusion plains)
- Bohn nodules: hard palate
- Epstein pearls: gum margins –> newborns, resolve spontaneously
- Milia en plaque: commonly post-auricular, erythematous, oedematous plaque with multiple milia
- Morphology: 1-2 mm, firm, white-yellow, subepidermal papules
- Onset: 40-50% infants, resolve spontaneously within the first 4 weeks of life
15
Q
Milia en plaque
A
commonly post-auricular, erythematous, oedematous plaque with multiple milia
16
Q
Bohn nodules
A
Milium on the hard palate
17
Q
Epstein pearls
A
Milium on the gums
18
Q
Milium histology
A
- Small epidermoid cyst with stratified squamous epithelial lining with a granular layer
- Contents: laiminated keratin
19
Q
Milium treatment
A
- incising the epidermis over the milium with a needle, scalpel or lancet and expressing the milium
- comedone extractor
- laser ablation and electrodesiccation
- multiple: topical retinoid
20
Q
Tricholemmal cyst clinical
A
- clinically indistinguishable from epidermoid cysts
- less common
- 90% located on the scalp
- solitary, multiple, can be inherited in an autosomal dominant fashion
21
Q
Tricholemmal cyst histology
A
Trichals are not saikals - pale
- Stratified squamous epithelium, without a granular layer
- Epithelium swollen and pale cells increase in bulk and vertical diameter towards the lumen
- Abrupt keratinization
- Cholesterol clefts
- Scalloped like lining
- Eosinophilic staiing
- perpendicularly oriented bundles of tonofibrils in the lining epithelial cells
- foreign body response may be around the cyst if prior wall rupture has occurred
22
Q
Tricholemmal cyst rx
A
- excision
- deliver themselves more easily with incision without rupture –> can tell at the time of excision whether tricholemmal or epidermoid
23
Q
Proliferating Tricholemmal Cyst clinical
A
- Distribution: 90% scalp
- Morphology: slow growing nodule on the scalp
- Complications: have a benign fashion, but very rarely metastases or spindle cell carcinoma development
24
Q
Proliferating Tricholemmal Cyst histology
A
Proliferating: I worry about SCC
- Stratified squamous lining with no granular layer
- Well circumscribed cyst, 25% have an epidermal connection
- lobular proliferations of squamous cells - often with palisading and some vitreous membrane formation
- Focal cystic areas
- cells undergo abrupt keratinization, and form dense homogenous keratin that fills cystic spaces
- Areas of epidermoid keratinization with formation of horn pearls and foreign body giant cell reaction
- well circumscribed, pushing borders surrounded by compressed collagen
- how its different to an SCC: lack of infiltrative growth into the surrounding stroma and abrupt tricholemmal keratinization
- marked atypia and infiltrative borders suggestive of aggressive behaviour
25
Q
Proliferating Tricholemmal Cyst rx
A
surgical excision
26
Q
Proliferating Epidermoid Cyst clinical
A
- more commonly in men, 20% in scalp
- dont spread
27
Q
Proliferating Epidermoid Cyst histology
A
- stratified squamous with a granular layer
- multilocular cystic spaces containing keratinous material or proteinaceous fluid
- subepidermal cystic tumours with a granular layer
- often connecting to the epidermis
- prolfierating epithelium extends into adjacent stroma, may show squamous eddies
28
Q
Proliferating Epidermoid Cyst rx
A
Excision
29
Q
Vellus Hair cysts clinical
A
- Morphology: numerous, dome shaped papules
- Distribution: commonly on trunk
- Course: can resolve via transepidermal elimination of cyst products, although most just persis, can become inflamed
- Symptoms: generally asymptomatic
- steatocystomas arise from the sebaceous duct and vellus hair cysts arise from the infundibulum –> overlap can occur
30
Q
Vellus Hair cysts histology
A
- small dermal cysts lined by stratified squamous epithelium with a granular layer, lumen with keratin and vellus hairs
- i think vellus hairs are the red spots
- with polarized light, vellus hairs are doubly refractile
31
Q
Vellus Hair cysts rx
A
- incision and drainage
- needle evacuation
- puncture followed by forceps assisted extraction
- topical retinoic or lactic acid
- laser ablation
32
Q
Vellus Hair cysts aetiology
A
- Genetics: autosomal dominant pattern
- Pachyonychia congenita: eruptive vellus hair cysts and steatocystoma multiplex
33
Q
Steatocystoma clinical
A
- Can be simplex or multiplex
- Morphology: few mm-cm, drain oily fluid if punctured
- Distribution: chest, axillae, groin, can have facial, acral variants and rare congenital linear form
- Symptoms: asymptomatic
- Course: persist
34
Q
Steatocystoma aetiology
A
- Aetiology:
- Inherited: autosomal dominant, due to KRT17 gene mutation
- Pachyonychia congenita: eruptive vellus hair cysts and steatocystoma multiplex - PC-17
Derivation: sebaceous duct
35
Q
Steatocystoma histology
A
- dermal cyst
- undulating stratified squamous epithelium without a granular layer
- Sebaceous glands in the wall
- Corrugated
- Red roof: (stea at the red roof inn) - eosinophilic cuticle
- may hav vellus hairs
- if has the above without sebaceous glands then is called a cutaneous keratocyst
36
Q
Cutaneous keratocyst
A
- reported in those with basal cell naevus syndrome
- similar looking to epidermoid cyst
- on histology have stratified squamous epithelium without a granular layer
- eosinophilic cuticle
- no sebaceous lobules
37
Q
Follicular hybrid cyst
A
- not distinctive clinically
- histologic variant of cysts with a stratified squamous lining - transition between epidermoid keratinization and tricholemmal or matrical keratinication
- been associated with naevoid BCC syndrome
38
Q
Pigmented follicular cyst
A
- usually solitary and occur primarily on the face of men
- deeply pigmented, may be confused clinically with a melanocytic naevus
- Histo: pore-like connection to epidermis, lined by stratified squamous epithelium that includes a granular layer, contains pigmented hair shaft
- clinical presentation, epidermal connection and pigmented terminal hair shafts rather than vellus hair shafts distinguish the pigmented follicular cyst from vellus hair cysts
39
Q
Dermoid cyst clinical
A
- Distribution: embryonic fusion plane - eye (lateral), forehead, neck
- Derivation: subcutaneous cyst of sequestered ectodermal origin
- Morphology: discrete, subcutaneous nodule, 1-4 cm in diameter, non-pulsatile, non-compressible, does not transilluminate
- Asymptomatic
40
Q
Dermoid cyst histology
A
- stratified squamous epithelium with a granular layer
- contain normal cutaneous structures such as hair, sebaceous lobules, eccrine glands, apocrine glands and smooth muscle
- hair shafts in lumen with keratinous debris
41
Q
Ear pit aetiology
A
Derivation: 6 tubercles - 3 each from the first 2 branchial arches, defective embryologic fusion with epithelial entrapment
- Cause:
- autosomal dominant sometimes, 0.5-1% of population has it
- Branchio-otic syndrome and branchio-oto-renal dysplasia
- Treacher Collins, hemifacial microsomia, cat-eye syndrom
42
Q
Ear pit clinical
A
Unilateral, right-sided
Infections can occur
43
Q
Ear pit histology
A
stratified squamous with granular layer
44
Q
Ear pit Rx
A
- simple excision
- if seen in a newborn –> need to look for associated syndromes and hearing loss
- infected –> abx
45
Q
Pilonidal cyst clinical and aetiology
A
- inflamed, painful cystic swelling in upper gluteal cleft or sacrococcygeal area
- Caucasian, males who are hirsute
- second decade of life
- Aetiology: controversial, some think congenital but most now think represents a foreign body response to entrapped hair
- can be seen part of the follicular inclusion tetrad - acne, HS, dissecting cellulitis and pilonidal cyst
- persistent exogenous hairs in the interdigital sapce of barbers or dog groomers may incite an encompassing epidermal proliferation
46
Q
Pilonidal cyst histology
A
- epidermal lined cyst or sinus tract
- cavities contain hair and keratin debris, surrounded by granulation tissue and mixed inflammation
47
Q
Pilonidal cyst treatment
A
Surgical
48
Q
What is decapitation secretion
A
describes apical portions of cytoplasm ofsecretorycells that project prominently as buds into a lumen
49
Q
Hidrocystomas - eccrine and apocrine clinical
A
- translucent, skin-coloured to bluish cysts on the face
- traditionally divided into apocrine and eccrine, or solitary (Smith) and multiple (Robinson)
- Can be associated with specific syndromes such as ectodermal dysplasia
- Appocrine:
- solitary - always alone
- adenomas of apocrine sweat gland coils
- Eccrine:
- solitary or multiple, and can get quite large
- enlarge with heat exposure, and regress in winter
- believed to be due to cystic dilation of eccrine ducts due to retention of eccrine secretions
50
Q
Apocrine hidrocystoma histology
A
- multiloculated cyst
- columnar cells
- Snouting: luminal bulbous protrusions and decapitation secretion
- decapitation secretion - ‘pinch off’
- flat, basal layer of elongated myoepithelial cells
51
Q
Eccrine hidrocystoma histolog
A
- 2 cs –> 2 layers of cuboidal
- uniloculate cyst with 2 layers of cuboidal epithelium with eosinophilic cytoplasm
- contains clear fluid
- often close to eccrine gland
- no decapitation secretion
- light microscopy: stain positively to milk fat globulin 1 and therefore are of apocrine origin
52
Q
Hidrocystoma rx
A
- simple excision, including via Gradle scissors
- electrodesiccation
- multiple eccrine: treated with daily application of topical 1% atropine in aqueous solution - although lesions reappear within days of discontinuing
- flattening after botox has been reported
53
Q
Bronchogenic cyst
A
- suprasternal notch, rarely anterior neck
- fistulous tract may connect to the epidermis
- rarely: present as pedunculated growth
- solitary, typically noted at birth
- very rarely malignant transformation
- represent respiratory erpithelium sequestered during embryogenic development of the tracheobronchial tree
- treatment is excision
Histo
- pseudostratified, ciliated, columnar epithelium with interspersed goblet cells
- cyst wall often contains smooth muscle and mucous glands and rarely cartilage
54
Q
Thyroglossal duct cyst
A
- midline cystic nodule on the anterior neck in kids and young adults
- arises from remnants of the thyroglossal duct (tract which the thyroid moves along from pharynx to anterior neck)
- tract connecting these cysts to the hyoid bone is frequently present, resulting in characteristic movement of the cyst with swallowing
- rarely can get thyroid carcinoma here
Histo
- cyst with pseudostratified columnar to squamous epithelium, no adjacent smooth muscle mucous glands or cartilage
- thyroid follicles - low cuboidal cells surrounding homogenous pink material in the cyst wall
55
Q
Branchial cleft cyst
A
- pre-auricular, mandibular and anterior border of the SCM muscle
- origin is controversial, 2 main theories:
- arise from branchial cleft remnants
- represent cystic alteration of embryonic epithelium or tonsillar epithelium within cervical lymph nodes
- mainfest 2nd or 3rd decade of life
- can get infected
- Histo: stratified squamous or pseudostratified ciliated colimnar, surrounded by lymphoid tissue
- Rx: excise, need CT or MRI for delineation
56
Q
Cutaneous ciliated cyst and ciliated cyst of the vulva
A
- uncommon
- lower extremities of young women
- few cm in diameter, and on rupture drain clear to amber fluid
- ?from mullerian ducts or from eccrine gland metaplasia
- vulva: more commonly of labia majora
- Hist:
- uni or multiloculated
- cyst wall is composed of simple cuboidal to columnar ciliated epithelium that may have papillary projections into the cyst lumen
- Rx: excision
57
Q
Median raphe cyst
A
- solitary and small
- young men on the ventral aspect of the penis, most commonly on or near the glans
- thought to develop from aberrant urethtral epithelium, don’t connect to the urethra
- Histo: stratified columnar epithelium (1-4 cells thick), occasionally mucin containing cells
- Rx: excision
58
Q
Omphalomesenteric Duct Cyst
A
- defect in the duct –> which is the foetal connection between the midgut and the yolk sac, normally it is obliterated and loses its intestinal attachment by 6 weeks gestation
- remnants of this duct can ocur anywhere between the intestines and the umbilicus
- spectrum of issues: Meckel diverticulum, umbilical-enteric fistulae, umbilical sinuses, and these cysts (umbilical polyp)
- Histo: ectopic gastrointestinal mucosa and must be distinguished from umbilical metastases of GI adenocarcinomas
- Ddx: cutaneous endometriosis
- Rx: imaging to exclude communication with GIT, then excision
59
Q
Urachal cyst
A
- connects the foetal bladder to the umbilicus and mormally closes during development –> fibrous tract
- when doesnt close then you get a urachus –> urine leakage from the umbilicus
- cyst results from incomplete urachal duct remnant
- these are super rare
- Histo: urothelial lining of cuboidal or columnar cells
- Rx: excision to prevent infection and development of adenocarcinoma
60
Q
Mucocele clinical and derivation
A
- Distribution: lower labial mucosa, floor of mouth, buccal mucosa, tongue
- Morphology: dome shaped, mucosa coloured to bluish, translucent papules or nodules
- Derivation: from a disruption of ducts of minor salivary gland –> accumulation of mucinous material, reactive inflammatory response and development of surrounding granulation tissue
61
Q
Superficial mucocele
A
Clear, tense vesicle. These are on the retromolar pad, posterior buccal mucosa and soft palate. these are short-lived, asymptomatic and recurrent. good ddx for immunobullous and viral
62
Q
Mucocele histology
A
- Mucosa + Cystic Space
- No epithelial lining, spaces are surrounded by chronic inflammation, mucin containing macrophages and granulation tissue
- Possible sebaceous gland adjacent, or salivary gland adjacent
- salivary glands may show chronic inflammation and fibrosis
- mucinous material: sialomucin - contains neutral and acid mucopolysaccharides - stain with PAS (former) and Alcian blue or colloidal iron (latter)
- numerous neutrophils and eosinophils in the cystic space or stroma (not true cyst since lacks lining)
- two types:
- pseudocystic space with surrounding macrophages and vascular loose fibrous tissue
- granulation tissue with mucin, muciphages and inflammatory cells
63
Q
Superficial mucocele histo
A
subepithelial vesicle filled with mucin and a surrounding sparse to moderate mixed inflammatory infiltrate
64
Q
Mucocele histo
A
- may resolve spontaneously
- excision, marsupialization, electrodesiccation, IL steroid injection or cryosurgery
65
Q
Digital mucous cyst clinical
A
- Distribution: commonly on dorsal surface of the distal phalanx of the finger
- Morphology: longitudinal depression in the nail plate may be seen distal to the cyst, skin coloured to bluish - drains clear, gelatinous material
66
Q
Digital mucous cyst cause
A
- Derivation: uncertain ?degenerative, ?extend from distal interphalangeal joint space
- pedicle connecting the cyst to the adjacent joint space can usually be demonstrated
67
Q
Digital mucous cyst histology
A
- clefts seen in dermis without an epithelial lining
- mucinous pool with stellate fibroblasts
- abundant acid mucopolysaccharides
- stain Alcian blue or colloidal iron
68
Q
Digital mucous cyst rx
A
I- L injection of steroid, sclerosing agents
- Repeated puncture and drainage
- Highest rate of success: surgical excision
69
Q
Ganglion clinical
A
- soft, cystic masses up to 4 cm in diameter
- commonly dorsal aspect of the wrist, volar wrist or fingers, dorsal aspect feet or knees
- rarely lateral elbow or anterior shoulder
- women
- uncomfortable
- Rare disorder: cystic ganglionisis - multiple lesions appear during childhood or adolescence
- frequently attached to a tendon sheath or joint capsule, but do not communicate with the joint space
- mucin present thought to be produced by local fibroblasts
70
Q
Ganglion histology
A
- myxoid change within conntective tissue –> forms cystic spaces
- these spaces coalesce into a dominant cystic space lined by fibrous tissue, sometimes with synovial lining
71
Q
Ganglion treatment
A
- early lesions can respond to several weeks of compression therapy
- Aspiration + IL steroids or excision
- recurrences are common
72
Q
Pseudocyst of the auricle
A
- scaphoid fossa of the ear in middle-aged men
- usually unilateral
- painless swelling, tend to arise over the course of a few weeks
- ?from chronic trauma
Histo - ‘hole in the cartilage’ - intracartilaginous cavity without an epithelial lining
- wall contains eosinophilic, amorphous material with small clefts
- fibrosis in the cavity
- no inflammation which would be seen with relapsing polychondritis
73
Q
Pseudocyst/cutaneous metaplastic synovial cyst
A
- solitary, tender subcutaneous nodules
- sites of prior trauma, particularly surgical
- preoperative diagnosis is that of a suture granuloma
- Histo: cystic cavity seen within the dermis that is not lined by epithelium, doesn’t communicate, variable cellular villous structures mimicking hyperplastic synovium protrude into the cavity. Villi are covered with fibrinous exudate
- Rx: excision
