Premalignant and Malignant Skin Tumors

Question 1

What condition is viewed as a precursor condition to squamous cell carcinoma, and what patient population is most susceptible?

Answer 1

Actinic Keratosis (AK)

Transplant patients are most susceptible to progression to squamous cell carcinoma, and the lesion is also more common in them

Question 2

How do actinic keratoses generally appear grossly?

Answer 2

Can be erythematous papules to red-brown plaques with scaly stratum corneum

In some cases, it may present with “cutaneous horns” or extensions of keratinic plaques above the surface of the skin which looks like a horn

Question 3

What are the histological findings for actinic keratosis? What typically causes these lesions?

Answer 3

Intraepidermal, partial thickness atypia of epidermis

• > dysplasia which is the precursor to SqCC
• > caused by sun damage, can be prevented by avoiding sun / using sunscreen

Question 4

What is the most common method of treating solitary superficial lesions of actinic keratosis?

Answer 4

Cryotherapy -> use nitrogen to freeze off the lesion and skin will regrow normally from basal layer

Question 5

What are other possible treatments for AK other than cryotherapy?

Answer 5

Field therapy with 5-FU and imiquimod

Photodynamic therapy (take up chemical into damaged skin and activate with light)

Question 6

What is the most common type of cancer in the US? What will happen if it’s untreated?

Answer 6

Basal cell carcinoma

Tumor grows slowly locally and invades / destroys surrounding structures. Only rarely metastases.

Question 7

How do basal cell carcinomas appear grossly and what are the major risk factors?

Answer 7

Generally appears as pink or pearly-white nodules with overlying telangiectasias. Can bleed, become erosive, and ulcerate in the center. May develop a raised, rolled border.

Risk factor: cumulative UV exposure

Question 8

What are the three main subtypes of BCC?

Answer 8

1. Nodular - shiny papule with telangiectasia
2. Superficial - flat erythematous patch
3. Sclerotic - scar-like

Question 9

What tumor does basal cell carcinoma often look like?

Answer 9

Often looks like melanoma -> can be speckled brown or black in color (due to containing melanin)

Question 10

What will histology show for a basal cell carcinoma?

Answer 10

Nodules of basal cells with peripheral palisading -> lining up around the periphery of nodules

Question 11

Where does basal cell carcinoma tend to arise, and what is the treatment?

Answer 11

Think BS

B: Upper lip - basal cell carcinoma
S - Lower lip - squamous cell carcinoma

Treatment for both of these entities is excision, though you can do all that fancy stuff you did with actinic keratosis as well

Question 12

What is the second most common skin cancer and what will the lesion generally look like?

Answer 12

Squamous cell carcinoma

Looks like dull red, firm nodules with adherent yellow-white SCALE. May ulcerate and have necrotic center + bleeding

Question 13

What are risk factors for squamous cell carcinoma?

Answer 13

1. Ultraviolet light exposure
2. Immunosuppression (i.e. transplants)
3. Chronic inflammation, i.e. due to chronically draining sinus tracts (i.e. from osteomyelitis) or scars from burns
4. Arsenic exposure -> causes hyperkeratosis

Question 14

Where does SqCC typically arise?

Answer 14

Often on lower lip, sunexposed areas of the face and upper extremities, hands especially, and then genitals (HPV-related)

Question 15

What SqCC’s are at high risk of metastasis?

Answer 15

Large tumors which are poorly differentiated, especially in immunosuppressed, on chronic wounds, or on ears / lips.

Metastatic tumors will also often show perineural invasion

Question 16

What does SqCC look like on histology and what defines that it is invasive?

Answer 16

Keratin pearls extending into dermis

Invasive when malignant cells breach the DEJ and invade the ermis

Question 17

What is a Keratoacanthoma? What does it look like / what is the prognosis?

Answer 17

Invasive squamous cell carcinoma variant with cup-like shape and keratotic debris in the middle (central keratotic core)

Prognosis - Rapidly progresses for 4-6 weeks, then often spontaneously regresses over months

Question 18

What is it called when a SqCC is in situ and when it is on the uncircumsized glans penis?

Answer 18

SqCC in situ (full thickness dysplasia) - Bowen’s disease

Penile shaft - Erythroplasia of Queyrat

Question 19

What is a verrucous carcinoma and where do they appear?

Answer 19

SqCC variant which presents as a warty plaque on plantar feet or distal fingers, often HPV-related

Question 20

When is Mohs micrographic surgery used?

Answer 20

In tumors at high risk anatomical sites (i.e. penis), in order to conserve tissue

Question 21

Are squamous cell carcinomas typically painful?

Answer 21

No, although if they are on places like the ear they can be.

Question 22

What is mycosis fungoides and what is the typical clinical progression / how is the diagnosis normally made?

Answer 22

Cutaneous CD4+ T-cell lymphoma

Typically a slow, fairly indolent course, resembles eczema with skin patches early (many years), but eventually progresses to plaques. Diagnosis is made via serial biopsies over several months.

Question 23

How do you differentiate Mycosis fungoides from Sezary syndrome, and what will the cells look like?

Answer 23

Need to do a CBC with peripheral smear examination, looking for CD4 cells with cerebriform nuclei (Sezary cells).

Typically, the leukemic stage is not yet reached in the patch / plaque stage of cutaneous manifestations

Question 24

What does the patch stage of mycosis fungoides resemble? What distribution is common/

Answer 24

Has red / scaly patches which are poorly demarcates and may have associated telangiectasia, bathing suit distribution is common

-> resembles eczema, psoriasis, or dermatophytosis

Question 25

What are aggregates of neoplastic CD4+ T cells in the epidermis called in mycosis fungoides?

Answer 25

Pautrier microabscesses

Question 26

What does the plaque stage of mycosis fungoides look like? What is the final stage?

Answer 26

Reddish-brown scaly, crushed plaques and flattened nodules

Final stage: Tumor stage -> ulceration may occur. Ultimately, massive dysfiguring tumor growth of face / extremities, even leading to leonine faces like leprosy can happen.

Question 27

What skin condition can mycosis fungoides cause once it has progresses to Sezary syndrome?

Answer 27

Erythroderma and generalized scaling (exfoliative dermatitis) -> skin becomes very red, palms and soles are thickened, with general pruritis / skin redness

-> patients need to be treated aggressively, possibly with extracorporeal photopheresis (like photodynamic therapy but directed towards T cells in blood)

Question 28

What are the four clinical variants of Kaposi sarcoma?

Answer 28

Classic - Older individuals of Mediterranean or Eastern European background

Endemic - Tropical Africa

Immunosuppressed - will improve upon cessation of immunosuppressive therapy

AIDS-associated / epidemic - multifocal or widespread disease

Bosch groups these last two together

Question 29

What causes Kaposi sarcoma and what does it look like histologically?

Answer 29

Caused by sexually transmitted infection with HHV-8

Low glade malignant proliferation of endothelial cells (irregular spindle-shaped cells forming vascular channels)

Question 30

How does classic Kaposi sarcoma appear?

Answer 30

Purple patches on distal lower extremities that progress proximally and become multifocal (looks a bit like venous lakes)

-> individual lesions may darken and thicken, eventually becoming brown (from hemosiderin) and wartlike

Question 31

What is the spread pattern of AIDS-associated (epidemic) Kaposi’s sarcoma?

Answer 31

Predilection for face (nose, eyelids, ears), and can even involve oral mucosa. Systemic involvement of GI tract / visceral organs makes it problematic
-> especially stomach / duodenum

Question 32

What does endemic Kaposi sarcoma involve?

Answer 32

Involves primary the lymph nodes of individuals in endemic regions, pretty aggressive, Africans age 20-50 years old

Question 33

What is the treatment for AIDS-associated KS and who tends to get it?

Answer 33

Antiretroviral therapy alone, or in combination with radiation / chemo

Occurs when CD4+ <200 cells/mL