Skin appendages Flashcards
IFK may be caused by infection of the hair follicles with HSV
False HPV
Pilar sheath acanthoma is most commonly found on the cutaneous upper lip in the elderly
True
Trichoadenoma microscopically resembles a tumour of the infundibular portion of the hair follicle turned at 90 degrees
True ‘Turnadeniner’
Comedo naevus is always present at birth
False can be at birth or can appear duirng adult life
Pilar cyst is another name for a sebaceous cyst
False Pilar cyst is a trichilemmal cyst
Pilar cysts can be inherited in a recessive manner
False AD
Females get trichilemmal cyst more than males
True
Trichilemmal cysts are relatively common and usually occur on the scalp
True
A proliferating trichilemmal cyst is a rapidly enlarging lesion which arises from a trichilemmal cyst
True
Proliferating trichilemmal cyst commonly becomes malignant
False malignancy rare but often dysplastic on histo and should be completely excised otherwise tend to recur
A trichilemmoma is a tumour of the external root sheath
True The outer root sheath is the ‘trichilemma’ Tumours include; Trichilemmoma Proliferating/normal Trichilemmal (Pilar) cyst Trichilemmal carcinoma
Trichilemmomas have clear cells which are PAS +ve and diastase labile
True contain glycogen
Trichilemmoma is seen on the face in elderly pts
False On face usually in young-middle age
A hair follicle naevus is a plaque composed of a cluster of vellus hair follicles
True may just look like dense patch of vellus hairs
Faun-tail naevus is the same as a Becker’s naevus
False It is a hair follicle naevus on the sacrum
Eruptive vellus hair cysts are a feature of pachyonychia congenita
True can also be sporadic or a familial trait
Eruptive vellus hair cysts develop on the back in the second decade of life
False on chest in second decade but rarely elsewhere including face
Eruptive vellus hair cysts pathologicallly strongly resemble epidermoid cysts but with hairs
False strongly resemble steatocystoma but with hairs Epithelial lined cyst located in the mid dermis
Eruptive vellus hair cysts are due to occlusion and cystic dilatation of vellus hair follicles
True
A trichofolliculoma is a flat leison with a single protruding hair
False small raised nodule with several gairs protruding from a single orifice
Trichofolliculoma is a tumour of the external root sheath
False Trichofolliculoma is a hamartoma of the pilosebaceous follicle - it is in the hair germ tumour group; o Trichofolliculoma o Trichoepithelioma o Desmoplastic trichoepithelioma o Trichoblastoma
Trichofolliculomas occur in young adults esp on the face and can also occur on the vulva
True Vulval trichoepithelioma is rare but is associated with VIN
Trichoepithelioma is a variant of trichofolliculoma
False Trichoepithelioma is a variant of trichoblastoma
Trichoepithelioma is a small slightly raised pearly lesion on the face
True
Trichoepithelioma occurs singly or multiply usually in young people
True
Trichoepithelioma is a sporadic lesion without associations
False cam be sporadic or familial AD trait some familial cases have Brooke-Spiegler syndrome Occur on the genitals in Bazex-Dupre-Christol
Epithelioma adenoides cysticum is a syndrome of multiple angiofibromas
False Rare syndrome of multiple large, yellow-pink or bluish trichoepitheliomas
Desmoplastic trichoepithelioma (DTE) occurs in young people and clinically may resemble a BCC
True Plaque with raised rolled edge - often looks even more BCC like than standard trichoepitheliomas do
Histologically DTE resemble a nodular BCC
False Can resemble sclerosing (morphoeic) BCC Alos closely resembles Microcystic adnexal carcinoma (MAC)
DTE conatins Merkel cells which stain with CK20 and can be used to differentiate it from MAC
True
Trichoepithelioma is the most common tumour arising in a naevus sebaceous
False Trichoblastoma is
There are reports of trichoblastoma arising after low dose depilatory Xray treatment (as used to be used for tinea corporis)
True
Trichoblastoma can be difficult to differentiate histologically from follicular BCC
True Merkel cells in trichoblastoma can help differentiate
Basaloid follicular hamartomas are associated with endocrine diseases
False with autoimmune disease e.g. alopecia, LE, MG
A pilomatrixoma is a hamartoma of the hair matrix
True main inner root sheath or matrix tumour
Pilomatrixoma accounts for 60% of hair follicle tumours
False 20% most common hair follicle related tumour
Pilomatrixoma occurs in children and young adults affecting both sexes equally
False F>M otherwise true
Pilomatrixoma is associated with Rubenstein-Taybi and Turners syndromes
True also; Gardner’s syndrome and variant MYH-associated polyposis (MAP syndrome) Myotonic dystrophy
Pilomatrixoma is a hard, 3-30mm subcutaneous lesion on the head, neck or arms
True
Pilomatrixoma should be completely excised as malignant change is common
False Malignancy rare but can recur if not completely excised Pilomatrocarcinoma tends to occur in older people (>70) who have long-standing lesions
A fibrofolliculoma is a tumour of the hair follicle mesenchyme (perifollicular connective tissue)
True along with; trichodiscoma perifollicular fibroma
Trichodiscomas occur as multiple small flat-topped papules on the lateral face
False ocur on central face
Familial trichodiscomas is pathognomonic of Birt-Hogg-Dube syndrome
False familial cases can occur other than in BHD
Acrochordons in BHD show differentiation into either fibofolliculoma type or trichodiscoma type
True
Birt-Hogg-Dube syndrome is due to mutation in the hamartin gene
False Folliculin gene FLCN
Fobrofolliculoma is arare lesion with multiple small, poorly-formed pilosebaceous folllicles in a striking fibrous stroma
True
Sebaceous adenoma and sebaceoma are easily disitnguished
False
Sebaceous adenoma and sebaceoma occur in elderly pts on sun damaged skin
False elderly pts but no association with UV damage
Muir-Torre accounts for 1-2% of Lynch syndrome (HNPCC)
True
Sebaceous adenoma and sebaceoma most often occur on the face and scalp and may be sessile, pedunculated or papilliferous
True often yellowish lesions resembling large firm sebaceous hyperplasias esp appear around the eyes
Sebaceous carcinoma accounts for
True
Sebaceous carcinoma mainly occurs in children and young adults
False mainly elderly, also middle age rare reports in children
smoking and UV predispose to Sebaceous carcinoma
False but immunosuppression, arsenic and XRT may be aetiological factors in rare cases
Sebaceomas with high mitotic activity may be wrongly diagnosed as ebaceous carcinoma on histo
True
Sebaceous carcinoma is a slow growing, yellow-orange tumour that favours the eyelids
True usually head and neck esp eyelids but away in Muir-Torre
Sebaceous carcinoma in Muir-Torre usually occur on head and neck sites
False Usually occur away from the normal head and neck sites
Sebaceous carcinoma occuring in the immunosupressed may show microsatellite instability
True Not always Muir-Torre
Sebaceous carcinoma may grow rapidly, invade early and metastasise frequently
False usually slow but can be rapid growth and invasion esp if on eyelid but metastasis very rare
Sebaceous carcinoma can show pagetoid spread on histo
True Often does esp in the more invasive ones around the eye
Mohs can be used for sebaceous carcinoma
True Rx of choice if available other wise complete excision
Apocrine hydrocystoma occurs in men 3x more than women
False M=F, adults any age
Apocrine hydrocystoma is more most common lateral to the lateral canthus
True
Apocrine hydrocystoma has no syndromic associations
False multiple lesions occur in the rare ecotdermal dysplasia Schöpf–Schulz–Passarge syndrome
Apocrine hydrocystoma can occur away from the perioccular region
True reported on axillae, digits and penis
Apocrine hydrocystoma with cytological atypia and mitotic activity and fibrous papillary projections should be designated syringocystadenoma papilliferum
False these are called apocrine cystadenoma should be completely excised
Topical phenol is suitable for multiple apocrine hydrocystomas
False TCA
Syringocystadenoma papilliferum (SCAP) occurs on the face and scalp of young adults
True can also be present at birth or develop in childhood can be asociated with an organoid naevus also reported on vulva, breast, ear, leg