Benign skin and soft tissue lesions & tumours Flashcards
(100 cards)
Classify and list benign pigmented lesions.
- Nevocellular
- Congenital: congenital nevi (small, medium, giant)
- Acquired: junctional, compound, intradermal nevi
- Special: halo nevus, spitz nevus
- Melanocytic
- Epidermal: ephilides, lentigo simplex, solar lentigines, nevus spilus, cafe au lait, becker’s nevus
- Dermal: Nevus of Ota/Ito, congential dermal melanosis, blue nevus
Describe acquired nevocellular nevi
- Acquired brown macule/papule composed of nevus cell nests
- Tend to be small, homogenous, smooth round symmetrical borders, sun exposed areas
- 3 types, tend to mature through these stages over time
- Junctional - flat, darker pigments, nevus cells at epidermal-dermal junction
- Compound - raised, nevus cells in epidermis, epidermal-dermal junction, dermis
- Dermal - raise, less pigmented, nevus cells in dermis only
Classify and describe congenital melanocytic nevi
- Typically classified by size (anticipated size at maturity)
- Small < 1.5cm2
- Medium - 1.5 - < 20cm2
- Small and medium have similar properties
- tan to brown, irregularly shaped; tend to darken, become elevated, have nodular properties and grow hair in puberty
- Treatment is excision, serial excision (medium) if symptomatic, clinical change or for cosmesis, malignant transportion is low (? 1%)
- Giant - > 20cm (6cm body / 9cm head in infant)
- pale brown and hairless to dark, hairy, verrucous, colour variegation +/- satellite lesions
- locations: trunk > extremities > H&N; may extend to leptomeninges - central lesions consider CNS involvement
What do you tell the parents of an infant born with a giant cutaneous CMN regarding prognosis and treatment planning?
- Prognosis is related risk of malignant transforation to melanoma - quote overall 5 to 10%
- among those who develop melanoma, 50% by 3 yrs; 60% by 7 yrs; 70% by adolesc
- RF: 3+, age of patient, posterior scalp/body, size (giant), sun exposure
- Would recommend surgical treatment for giant, non-surgical treatment with close observation for small/medium
- Non-operative treatment
- close observation: serial exams, photography, clinical assessments
- Operative
- simple excision
- exision and grafting
- serial excision
- tissue expansion and exision or locoregional flap of expanded tissue
What are the indications and goals for operative treatment of CMN?
Goals
- excise as much nevus in as few stages as possible
- preserve function and cosmesis
Indications
- Cosmetic / social concern
- Functional complaints - symptomatic: pruritis, pain, hair, impaired function
- Clinical change
- Risk of malignant transformation (giant)
How are congenital nevis differentiated from acquired nevi on histopathology?
Congenital nevi have nevus cells of NCC origin in ectopic locations
- Nevomelanocytes in epidermis
- Sheets, nests, cords and single cells in reticular dermis and SC tissue and btwn collagen bundles
- Nevomelanocytes in epidermal component of appendages, piloerector muscles
- Neurovascular infiltration
- Perivascular and perifollicular distribution
What is your differential for a congenital nevus?
- Congenital: Nevus of Ito/Ota, dermal melanosis, nevus sebaceous
- Acquired: acquired nevus, cafe au lait, becker’s nevus, nevus spilus
what syndromes do you see cafe au lait spots
NF-1
McCune-Albright
What are treatment options for nevus of Ota/Ito
– Q switched ruby/Nd:YAG laser
Differential diagnosis blue nevus
- Malignant nodular melanoma
- Metastatic melanoma
- Kaposi sarcoma
- Venous malformation
Why are congenital dermal melanoses (“mongolian spots”) seen as a blue colour?
Because of the Tyndall effect – Long wavelength light (reds) is transmitted and therefore pass by melanin (brown/black in colour), while short wavelength light (blues) is scattered, some being reflected backwards to the skin surface as blue colour
What is the histopathological definition of atypical nevus?
- proliferation of intra-epidermal melanocytes seen singly or in irregular nests along the basal layer or just above the rete ridges
- variable and discontinuous melanocytic cellular atypia
What is FAMM syndrome?
familial atypical mole and melanoma syndrome
- > 50 atypical moles + FHx of 1st/2nd degree relative w/ H/O melanoma
- AD inheritance
- 10% risk / 10 years; 100% lifetime risk
- Prophylactic excision does not change prognosis because melanoma can be de novo
- Photographs & monitor; excise when they change / express worriesome featues
What is Waardenburg syndrome?
Congenital absence of melanocytes from skin, hair, eyes, or stria vascularis of the ears resulting in auditory (deaf) & Hypo-pigmentary Disorders, cleft lip and palate
Define and describe neurocutaneous melanosis, including clinical symptoms, risk factors, treatment considerations.
· NCM is defined as a congenital disorder including multiple (> 3) or giant melanocytic nevi and infiltration of brain or leptomeninges by abnormal melanin deposits
· Triad – Fox’s 1972 diagnostic criteria: (radiopaedia.org; Kadonaga et al, acad dermatol 1991) -
o multiple or giant melanocytic nevi with leptomeningeal melanosis or melanoma
o no evidence of malignant change in cutaneous lesions
o no evidence of malignant melanoma in any organ except for leptomeninges
· Risk Factors – any size Congenital Nevocellular Nevi on scalp, neck, or spinal midline; giant CNN crossing the midline; satellitosis in these locations increases risk
· Clinical features – symptoms present at median age of 2 years à (signs consistent w/ increased ICP or SOL): hydrocephalus, seizures, focal neurologic deficits
· Imaging - MRI with gadolinium: detects melanin; do for all children with risk factor(s) by 6 months
· Extremely poor prognosis; progressive deterioration to death
· Treatment – Symptomatic: delay cutaneous excision d/t poor prognosis; excision, radiation, chemotherapy, interferon, retinoids
List types of biopsy, and ideal type of biopsy
Types:
- Shave
- FNAB
- Core, truCut
- Incisional
- Mapping
- Excision
Ideal:
- Excisional biopsy with 1-2mm margin
What is Cowden syndrome?
Multiple trichilemmomas, breast Ca, thyroid Ca, colon CA
What is Muir-Torre Syndrome?
– sebaceous neoplasm (adenoma, carcinoma) + ≥ 1 visceral malignancy (colon cancer>GU), keratoacanthoma, BCCs, ?subtype of hereditary nonpolyposis colorectal cancer (HNPCC)
What is Cowden Sydrome?
· Cowden Syndrome
o Physical Features – trichilemmomas, mucosal papillomas, multiple benign skin lesions
- also adenoid facies, craniomegaly, arched palate, scrotal tongue, sclerotic fibromas, punctate palmoplantar keratosis, acral keratosis,
o Systemic neoplasms – breast adenocarcinoma (age: 20s), breast fibroadenomas, GI polyps, thyroid cancer
List benign epidermal, appendage, mesynchymal lesions
- Epidermal
- Seborrheic keratosis
- Clear cell acanthoma
- Achondroma
- Veruca vulgaris
- Epidermal cyst
- epidermal cyst
- dermal cyst
- milia
- Appendage
- Trichoepithelioma
- Tricholemmoma
- Pilomatrixoma
- Appendage cyst
- Pilar cyst
- Sebacceous gland
- Sebaceous hyperplasia
- Sebaceous adenoma
- Nevus sebaceous (of Jadassohn)
- Eccrine
- Poroma
- Syringoma
- Spiradenoma
- Apocrine
- Cylindroma
- Mesenchyme
- Vascular: pyogenic granuloma, glomus (other vascular tumours/malformations), angiofibroma
- Nerve: neuroma, schwannoma, neurofibroma
- Fibrous: DF, nodular fasciitis
- Fat: lipoma
- Histiocytic: xanthoma
What are the diagnostic criteria for neurofibromatosis?
NF1 - > 2 of the following
- > 2 NF or > 1 plexiform NF
- > 2 Lisch nodules
- Optic glioma
- > 6 CALMs (> 5mm kid, > 15mm adult)
- Axillary / inguinal freckling
- Distinctive osseous lesion
- FHx (1st degree)
NF2 -
- Bilateral acoustic neuroma OR
- FHx and Unilateral acoustic neuroma or 2 of:
- Schwannoma
- Glioma
- Neurofibroma
- Meningioma
- Juvenile posterior subcapsular opacity
- FHx and Unilateral acoustic neuroma or 2 of:
Describe seborrheic keratosis
- Description: skin colour to pigmented waxy, “stuck on” acquired lesion
- Patients: typically older
- Location: typically face and trunk
- Path: acanthosis, parakeratosis, hyperkeratosis, papillomatosis
- Management:
- Observation, a-hydroxy-acid, TCA, cryo, EDC, shave, excise
- Differential: flat pigmented and raised pigmented lesion differential
- Leser-Trelat sign - sudden multiple SK associated w internal cancer or malignant acanthosis nigricans
What is clear cell acanthoma?
Benign epidermal lesion that is raised, red, rare, slow growing; treat with excision
Path: large epidermal cells filled with glycogen (appear clear)
Location: legs and covered wiht thin crust (peripheral collarette)
Describe epidermal cyst
Description: subcutaneous nodule, mobile, punctum, +/- history of trauma that arises from epidermis / epithelium of hair follicle
Histopathology: filled with keratin and sebum, lined with stratified squamous epithelium (not stratum corneum though)
Management: if actively infected: I&D, PO Abx, delay excision; if not actively infected: excise w/ ellipse of skin including the punctum