Tumors I & II (Swick) Flashcards
these two topical agents are used to treat actinic keratosis
topical 5-FU and Imiquimod
*Imiquimod is also indicated for the treatment of genital warts, and 5-FU when administered systemically is used for the treatment of colon cancer.
Which of the following statements about squamous cell carcinoma is FALSE?
A. Most cases are due to chronic long term UV exposure
B. Histology shows keratin pearls.
C. Approximately half are attributed to a loss of function mutation in the hedgehog signaling pathway.
D. Risk of metastasis is low when recognized early.
E. A shave or punch biopsy is sufficient for diagnosis
C
This is basal cell carcinoma - loss of function in PTCH1 leads to loss of control of Hh signaling pathway. This loss of inhibition is demonstrated particularly in the hair follicle, which is dependent on Hh for signaling and harbors stem cells that then begin to proliferate out of control.
histology of these epithelial lesions: pseudo-horn cysts opening to the surface and flat-bottomed epidermal thickening (acanthosis):
seborrheic keratoses
histology shows elongated dermal papillae with a fibrotic or fatty core
acrochordons (skin tags)
*associated with weight gain, diabetes, and pregnancy
nevi that are thought to arise from neural crest melanocytes that migrated to and stopped in the dermis (see below) instead of the epidermis during embryogenesis
blue nevi
these lesions are derived from the infundibular (top) portion of a hair follicle, have “cheesy” appearing contents with an overlying punctum
epidermoid cysts
histology shows:
- lots of blue, due to increased nuclear/cytoplasmic ratio
- mucin-stromal retraction
- lack of keratnization
basal cell carcinoma
benign tumor of mature adipose tissue; no treatment necessary unless symptomatic
lipoma
*looks like epidermoid cyst, but is slightly softer and has no puntcum
pink firm papules, often appearing on women’s shoulders or legs after minor localized trauma; characteristic dimpling when pinched (positive Fitzpatrick sign)
dermatofibromas
most common skin cancer in caucasians that is locally destructive with low mortality, and is associated with a history of intermittent intense UV exposure
basal cell carcinoma
disorder of hypopigmentation resulting from non-producing melanocytes
oculocutaneous albinism
clinical presentation is varied, and may appear as:
- flesh colored pearly papules with arborizing blood vessels,
- crusted like psoriasis, or
- flat and discolored like a scar
basal cell carcinoma
this is the most important prognostic factor in malignant melanoma
Breslow depth - measured from granular layer to deepest portion of melanoma with dermal invasion
*which is why a suspicious pigmented lesion needs to be biopsied into the fat; a full thickness punch biopsy or excisional biopsy will do
acquired patchy depigmentation of skin due to absence of melanocytes, often around facial openings and sites of trauma (eg. elbows, knees, hands and feet)
vitiligo
lentiginious hyperplasia (ie, melanocytic growth in a linear spread) with melanocytes spreading up the sides of rete ridges but not growing into the epidermis is characteristic of these nevi
dysplastic nevi
pigmented or skin colored papules (rarely nodules) with symmetry and border regularity that are confined to the dermis
dermal nevi
evenly pigmented papules (rarely nodules) that are found in both the dermis and epidermis, are flat-toppped, and have symmetry and border regularity
compound nevi
symmetric flat macules confined to the epidermis with even pigmentation and regular borders
junctional nevi
Which of the following statements about melanocytic nevi is FALSE?
A. They are benign accumulations of melanocytes that are usually acquired throughout childhood and young adulthood
B. Most nevi have BRAF and NRAS mutations
C. They tend to peak in number and size at age 40, then start to go away
D. They are considered true hamartomas - disorganized in their distribution but have normal cell cycle regulation
E. The number and type of nevi are secondary to genetic predisposition and early UV exposure
D.
Mealnocytic nevi are actually considered true neoplasms instead of hamartomas.
“mask of pregnancy”; more common in darker skin types
melasma (chloasma)
this is the second most common cause of skin cancer in Caucasians and is characterized by scaly erythematous papuls or nodules with a keratinous core or ulcer
squamous cell carcinoma
histology of this lesion shows:
- keratinization
- no granular cell layer
- central compact pink keratin
trichilemmal (pilar) cysts
All of the following statements regarding actinic keratosis are true EXCEPT:
A. It is an in-situ premalignant dysplasia of keratinocytes due to chronic sun exposure
B. 1 in 10 cases progress to basal cell carcinoma
C. It is characterized by a rough “sandpaper” feel when palpated
D. Histology shows less than full thickness epidermal atypia, with alternating para and ortho (hyper) keratosis
E. It is commonly caused by a p53 mutation
B. 1 in 10 cases will progress to squamous cell carcinoma.
a subtype of melanoma in which chronic sun damage plays a big role
lentigo maligna melanoma
benign proliferation of the epidermis, very common in people over age 30, waxy brown stuck-on appearing macules, papules and plaques
seborreheic keratoses
everyone has at least one of these little guys by the time they’re in their 30s, but not PAs, we be goin backwards ya’ll
cherry hemangiomas
these epithelial lesions result from activation of the transmembrane tyrosine kinase receptor FGFR3
sebhorreic keratoses
All of the following are risk factors for melanoma EXCEPT:
A. Mutations in the CDKN2A gene (a kinase inhibitor)
B. 3 or more dysplastic nevi
C. Pale skin, red or blone hair, tan poorly/burn easily
D. Chronic UV exposure
E. Family history of melanoma
D.
Unlike squamous cell carcinoma, melanoma is associted with intense sun exposure in early life rather than chronic UV exposure
histology shows: hyperpigmented, elongated rete ridges
solar lentigo
these asymmetric “fried egg” nevi are not necessarily premalignant lesions, although when they appear in multiples they are a phenotypic marker for increased risk of developoing melanoma, especially with a family history
dysplastic nevi
All of the following are characteristics associated with superficial spreading melanoma EXCEPT:
A. Early vertical growth phase
B. Upward spreading melanocytes
C. Lentiginous growth
D. Irregular nesting of melanocytes
E. Irregular color on skin
A. This is a characteristic associated with nodular melanoma, and is a negative prognostic factor of that type
these immovable lesions are derived from the isthmus (middle) portion of the hair follicle, mostly occur on the scalp, and may be inherited in an autosomal dominant manner
trichilemmal (pilar) cysts
*NO punctum!
All of the following are negative prognostic factors of melanoma EXCEPT:
A. Ulceration
B. High mitotic rate
C. Lymph node involvement
D. Regression
E. Inflammation in the tumor
E. This is a positive prognostic factor, indicating a vigorous host immune response to the tumor.
