Download MBBS Dermatology PPT 18 Malignant Skin Tumors Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Dermatology PPT 18 Malignant Skin Tumors Lecture Notes

Malignant Skin Tumors

Malignant tumor

? A tumor is an abnormal mass of tissue - growth of which exceeds & is

uncoordinated with that of normal tissue with capacity to metastasize

to lymph nodes and other organs

? Deals chiefly with the malignant tumors arising from epidermal cells
? Basal cell carcinoma
? Squamous cell carcinoma
? Malignant melanoma

Basal cell carcinoma (BCC)

? The most common cancers in humans
? All BCCs - Mutations activating the Hedgehog signaling pathway
? Exposure to UV light
? Associated with PTCH1 gene mutation in most cases
? BCCs are locally destructive but rarely metastatic
? BCCs - primarily treated by surgical excision, electrodesiccation &

curettage, Mohs micrographic surgery and topical agents

? BCC - The most common cancer in humans
? Estimated - >3 million new cases occur each year in the USA
? Men - affected slightly more often than are women
? Tumors - More frequent in patients older than 60 years of age
? Majority of BCCs- located on the head and neck

Risk factors

? Risk factors for BCC - ultraviolet radiation (UVR) exposure, light hair

and eye color, northern European ancestry and inability to tan

? BCC is rare in dark skin - the inherent photoprotection of melanin &

melanosomal dispersion
Clinical Features

? Subtypes
?Nodular BCC - the most common clinical subtype
?Pigmented BCC - a subtype of nodular BCC that exhibits increased melanization
?Superficial BCC - most commonly on the trunk
?Morpheaform (sclerosing/infiltrating) BCC - an aggressive growth variant
?Basosquamous carcinoma - a form of aggressive growth BCC; can be confused

with squamous cell carcinoma (SCC)

?Fibroepithelioma of Pinkus

Clinical Features

? Presence of any nonhealing lesion Should raise the suspicion of

skin cancer

? BCC - usually on sun-exposed areas of the head & neck
? Can occur anywhere on the body
? Commonly seen features - translucency, ulceration, telangiectasias,

and the presence of a rolled border

? Characteristics - Differ for different clinical subtypes

Nodular BCC

? The most common clinical subtype
? Occurs most often on the sunexposed areas of the head & neck
? Appears as a translucent papule or nodule
? Usually telangiectasias and often a rolled border
? Larger lesions with central necrosis - referred to by the historical term

`rodent ulcer'

Pigmented BCC

? A subtype of nodular BCC ? exhibits increased melanization
? Pigmented BCC - Presents as a hyperpigmented, translucent papule

Superficial BCC

? Superficial BCC - most commonly on the trunk
? Appears as - a well-demarcated erythematous patch
? The DD nummular (discoid) dermatitis
? An isolated patch of "eczema" that does not respond to treatment -

raise suspicion for superficial BCC

Morpheaform BCC

? An aggressive growth variant
? Lesions of morpheaform BCC - have an ivorywhite appearance
? May resemble a scar or a small lesion of morphea
? The appearance of scar tissue [in the absence of trauma/ previous surgical

procedure or the appearance of atypical-appearing scar tissue at a previously

treated lesion] - alert for possibility of morpheaform BCC

? The extent - often larger than the clinical appearance

Basosquamous carcinoma

? A form of aggressive growth BCC
? Can be confused with squamous cell carcinoma (SCC)
? Histologically - Shows both basal cell and SCC differentiation in a

continuous fashion

? Diagnosis - Accurate interpretation of the skin biopsy results
? The preferred method of biopsy - shave biopsy, punch biopsy
? Punch biopsy - Useful for flat lesions of morpheaform BCC & for

recurrent BCC occurring in a scar

? During biopsy - adequate tissue


? Management of BCC - guided by anatomic location & histological


? Approaches include standard surgical excision or destruction by

various other physical modalities, Mohs micrographic surgery (MMS)

topical chemotherapy

? Best chance to cure - Through `adequate initial treatment'

recurrent tumors are more likely to be resistant to further treatments

? May cause further local destruction

Mohs micrographic surgery

? Developed in 1938 by Frederic E. Mohs, a general surgeon
? A microscopically controlled surgery used to treat common types of

skin cancer

? During the surgery, after each removal, the tissue is examined for

cancer cells

? Provides informed decision for additional tissue removal
? Improves prognosis - After 5 years, MMS-treated BCCs recurred in

1.4% of primary & 4% of recurrent tumors

? Preferred treatment for any BCC where tissue conservation is desired
? Standard surgical excision
? Curettage & desiccation
? Cryosurgery
? Imiquimod (5% cream)
? 5-Fluorouracil
? Photodynamic therapy (PDT)

Squamous cell carcinoma (SCC)

? SCC - second most common skin cancer, in immunocompetent after

basal cell carcinoma

? The most common skin cancer - in immunosuppressed organ

transplantation recipients

? Majority of SCC - present with early-stage disease
? Prognosis - excellent in the majority of cases
? Risk of developing metastasis from SCC is generally low
Risk factors

? Ultraviolet radiation (both UVB and UVA) ? most important

environmental risk factor for the development of SCC with a strong

dose-response association

? Genetic predisposition - potentiate the risk of environmental factors

such as UVR

? Clinical skin phenotypes - Light complexion (as in photo types I, II)

? Physical & chemical carcinogens- Arsenic, used in various

medications, tainted wine and unprocessed well water may stimulate

skin carcinogenesis; Cutting oils - a risk of SCC development in certain

industrial occupations; SCC on the scrotum of chimney sweeps -

attributed to chronic exposure to ash & polycyclic aromatic

hydrocarbons derived from carbon compounds (e.g. coal tar)

? Immunosuppression including iatrogenic (e. g. solid organ

transplantation recipients, with autoimmune or rheumatoid disease),

Hematopoietic stem cell transplantation, Infection with HIV/AIDS

? Viral infection ? HPVs
? Chronic inflammation & chronic injury of the skin ? chronic ulcers

(Marjolin's), burn scars & radiation dermatitis

? Chronic inflammatory disorders - discoid lupus erythematodes,

mucosal & hypertrophic lichen planus, lichen sclerosus & dystrophic

epidermolysis bullosa

? SCC incidence - increases with age; most patients =/> 60
? Higher in men than in women
? Sun-sensitive individuals with red hair, blue eyes & fair complexion -

higher risk than individuals with darker pigmentation

? Race- Australians, exposed to very high, long-term UVR levels ? more

likely to develop SCC than other populations

Clinical Features

? Variable & depends on the histologic subtype and location
? Typically, SCCs arise on sun-exposed areas
? The face, head, and neck region & the forearms & dorsum of the


? The typical clinical finding ? includes slowly enlarging, firm, skin-

colored to erythematous plaques or nodules

? Marked hyperkeratosis
? Ulceration, exophytic or infiltrative growth patterns - seen

Verrucous SCC

? Verrucous SCC - a slowly growing ulcerated plaque or an exophytic

cauliflower-like slowly growing tumor

? Typical locations
? Oral cavity (oral florid papillomatosis)
? Genitoanal region (giant condyloma acuminatum; Buschke-L?wenstein)
? Plantar skin (epithelioma cuniculatum)
? Amputation stumps
? Less common than other forms of invasive SCC


? The standard pathology report to indicate:
? Histologic subtype (acantholytic, spindle cell, verrucous, or

desmoplastic type)

? Grade of differentiation (G1 to G4)
? Maximum vertical tumor diameter in millimeters
? Extent of dermal invasion (Clark level)
? Presence or absence of perineural, vascular, or lymphatic invasion
? Information about whether the margins are free or not

? Treatment modality for the primary lesion - major determinant for

the risk of local recurrence

? Ideal management - local tumor control along with maximal

preservation of function and cosmesis

Surgical excision

? Surgery excision - preferably microscopically controlled surgery (Mohs

surgery) - primary mode of therapy

? For localized lesions - cure rate of 95%
? SCC - local in-transit metastasis- may be removed by wide surgical

excision or treated by irradiation of a wide field around the primary


? Treatment of nodal metastasis - lymph node dissection, radiation, or

a combination of both
Other therapies

? Topical therapeutic treatments- e.g. imiquimod, topical or

intralesional 5-fluoruracil, cryotherapy & PDT ? Lack of evidence for

the efficacy

? Radiation therapy - patient preference and other factors, e.g.

problematic locations for surgery

? Limited data on the efficacy of chemotherapy for metastatic SCC
? Standard options in metastatic or unresectable disease ? systemic

platinum-based chemotherapeutic regimens, 5-

fluorouracil/capecitabine, or monotherapy/chemotherapy with


? Majority of SCCs- low risk
? If early stage- result in a high cure rate with excellent prognosis
? Prognosis for locally advanced SCC at the time of diagnosis & patients

with progressive disease after first-line surgical therapy - usually poor

? A poorer outcome of immunosuppressed patients with advanced



? Melanoma (Gr. melas [dark], oma [tumor]) - malignant tumor arising

from melanocytic cells

? Can occur anywhere where melanocytes are found
? The most frequent type - cutaneous melanoma
? Also at the mucosal, the uveal, or even the meningeal membrane
? 10% melanomas ? detected by lymph node metastases [with so-

called "unknown primary"]

? Rising incidence worldwide - Countries with white inhabitants, with

highest incidence rates in Australia (35 new cases/year/100,000)

? North America (21.8 new cases/100,000)
? Europe (13.5 new cases/100,000)
? Median age - for melanoma diagnosis is 63 years with 15% being <45


? Melanoma ? Accounts for only 4% of all skin cancer diagnoses in the


? Responsible for 75% of skin cancer deaths

Risk factors

? History of sunburns and/or heavy sun exposure
? Fitzpatrick skin phototypes I & II
? Blue or green eyes, blonde or red hair, fair complexion
? >100 typical nevi, or any atypical nevi
? Prior personal or family history of melanoma
? p16 mutation
Clinical Features

? Subtypes
?Superficial spreading melanoma
?Nodular melanoma
?Lentigo maligna
?Lentigo maligna melanoma
?Acral lentiliginous melanoma
?Desmoplastic melanoma
?Mucosal melanoma

Superficial spreading melanoma

? Most common subtype, accounting for approximately 70%
? Most common on intermittently sunexposed areas
? The lower extremity of women; the upper back of men
? Irregular borders and irregular pigmentation
? May present subtly as a discrete focal area of darkening
? Varying shades of brown typify most melanocytic lesions
? Also aspects of dark brown to black, blue-gray, red, and gray-white

(which may represent regression) may be found

Nodular melanoma

? Approximately 15%-30% of all melanomas
? The trunk - the most common site
? Remarkable for rapid evolution - often arising over several weeks to


? May lack an apparent radial growth phase
? Typically appears as a uniformly dark blue-black or bluish-red raised


? 5% are amelanotic

Lentigo maligna & Lentigo maligna melanoma

? Lentigo maligna - melanoma in situ with a prolonged radial growth


? Eventually becomes invasive Lentigo maligna melanoma
? Diagnosed most commonly in the seventh to eighth decades

(uncommon before the age 40)

? Most common location - the chronically sun-exposed face, on the

cheeks and nose in particular

? Clinical appearance - flat, slowly enlarging, brown, freckle-like macule

with irregular shape & differing shades of brown and tan


? Usual y based on metastatic disease - symptoms associated with the

affected organ

? Pain (any metastases)

? Convulsion (brain metastases)

? Instabilities, # - (bone metastases)

? Later - symptoms associated with progression of the disease & death in the

pal iative setting

? Cutaneous changes - localized or diffuse hypo- or hyperpigmentation

? Development of a melanoma-associated vitiligo [an accompanying

autoimmune disease against melanocytes] - in 4%; associated with a better


? Early detection - the key to improve prognosis
? Melanoma - Change in color and increase in size (or a new lesion) are

the 2 most common early characteristics noticed by patients that may

be useful in discriminating between melanoma and other benign


? Physical examination
? Dermascopy

? Pathology- Excisional skin biopsy
? Large lesion and/or located on anatomic areas such as the palm/sole,

digit, face, or ear, an incisional skin biopsy may be performed

? Lymph node examination f/b USG/excisional biopsy
? Tomographic investigations like computed tomography (CT), magnetic

resonance imaging (MRI) & positron emission tomography (PET) -

generally not recommended at the stage of primary melanoma - rate

of false positive findings is far too high (8%-15%), e.g. unspecific lung


? The standard of therapy - wide local excision (WLE)
? The purpose - to prevent local recurrence due to subclinical persistent


? The risk of satel ite metastases - related to primary melanoma thickness
? Current recommendations on the clinical margins - depending on the

Breslow thickness of the primary

?For melanoma in situ - a 0.5-1-cm margin
?For melanoma <1?mm Breslow depth ?a 1-cm margin
?For melanoma 1 to 2?mm thick - a 1- to 2-cm margin
?For melanoma >2?mm thick - a 2-cm margin is recommended

? Wider excisions with up to 5-cm margins - not show a benefit for local

recurrence rate

? Standard of therapy for macroscopic (stage II B/I IC) lymph nodes ?

CLND of the involved regional basin

? Uncontrolled nodal disease - Major cause of melanoma-related

morbidity with a significant high negative impact on QoL

? CLND for regional metastatic melanoma - associated with long-term


Adjuvant therapy

? Adjuvant therapy - for patients with surgically resected disease who

are at high risk for relapse such as those with thick primary

melanomas or nodal disease

? Interferon-alpha
? Anti-CTLA-4 antibody (ipilimumab) ? an immune checkpoint blocker
? Adjuvant radiotherapy after CLND

This post was last modified on 07 April 2022