2/8/16 - Exam 3

Question 1

Sebaceus hyperplasia - sebaceous gland

Answer 1

Clinical
• Common benign tumor of oil gland
• Increasing frequency after middle age
• Sunlight induced?
• Distribution- face>trunk>extremities
• Primary lesion- 1-6 mm yellowish-white papule (globules) with central dell
• May be component of Muir-Torre syndrome

Treatment not necessary

Question 2

Differentiate between skin tumors that are benign and those that are malignant or have malignant potential.

Answer 2

-

Question 3

Nevus sebaceus - sebaceus gland

Answer 3

Clinical - A hamartoma that most commonly presents as a papillomatous, yellow-orange linear plaque on the face or scalp. Lesions on the scalp are associated with alopecia.
Rapid growth occurs at puberty with enlargement of sebaceous glands and epidermal hyperplasia.

No treatment necessary, 10-30% result in neoplasm

Question 4

Neurofibromatosis Type 1:

Answer 4

•AD inheritance with variable expression
•50% of cases due to spontaneous mutations
•Defect in neurofibromin gene, a tumor suppressor, on chromosome 17 for NF-1
Diagnosis requires 2 or more of the following criteria
1. Six or more café au lait macules more than 1.5 cm in diameter (more than 0.5 cm
diameter in children)
2. Two or more neurofibromas, or 1 plexiform neurofibroma
3. Axillary or inguinal freckling (Crowe’s sign)
4. Optic glioma
5. Two or more Lisch nodules
6. Distinctive osseous lesion, such as sphenoid wing dysplasia or thinning of the
long bone cortex
7. A first degree relative (parent, sibling or child) with the disorder

Question 5

Name two types of vascular tumors:

Answer 5

hemangioma and cherry angioma

Question 6

An example of a vascular malformation would be a…

Answer 6

porn wine stain

Question 7

Two types of Keratinocyte based tumors are

Answer 7

– Seborrheic keratosis

– Actinic keratosis

Question 8

Infantile Hemangioma

Answer 8

Clinical Appearance
Strawberry (capillary) hemangiomas are benign vascular proliferations and the most common benign tumor of childhood. They appear by 2 months of age, with 1/3 present at birth. The grow rapidly over the first year of life, then they involute slowly at about 10% per year, so that 50% have resolved by age 5 and 90% have resolved by age 9.

Histology
There is a dermal proliferation of capillary-sized endothelial cell-lined vessels. The cells stain with placenta-associated vascular markers including GLUT-1. One theory is that hemangiomas arise from embolized placental cells or from invading angioblasts that differentiate toward a placental phenotype.

Question 9

Cherry Angioma

Answer 9

Clinical
• Distribution- primarily truncal
• Typically multiple- up to many hundreds
• Primary lesion
• 1-4 mm in size
• bright red, smooth-topped papules
• occasionally pedunculated
• Complications- none except for trauma

Question 10

Acrochordons

Answer 10

All physicians should be able to recognize these benign skin growths. Skin tags commonly occur in areas of rubbing including the neck, axilla and infra-mammary area in women. No treatment is necessary for these common skin growths as they are benign with no malignant potential. They can, however, be removed if bleeding from irritation or rubbing on clothing. The most common way to remove these lesions is by freezing (cryosurgery) with liquid nitrogen or by cutting them off.

Question 11

Dysplastic nevi

Answer 11

(atypical nevi, Clark’s nevi, nevi with disordered architecture and cytologic atypia) are a subgroup of nevi which have an irregular outline, variable pigmentation, indistinct borders, and can be larger than 6mm in diameter. Often described as having a “fried-egg” appearanceThe upper dermis usually shows fibrosis and contains a host response of lymphocytes.

Question 12

Explain the clinical utility and indications for the following diagnostic procedures in dermatologic patients: tzanck smear, gram stain, KOH prep, Wood’s light exam, and mineral oil (wet prep) for scabies.

Answer 12

?

Question 13

For common cutaneous fungal infections, including dermatophyte infections, candidiasis, and tinea (pityriasis) versicolor ‐ recognize the clinical characteristics and identify the etiologic agent.

Answer 13

Dermatophyte - food source is keratin, see hyphae with GMS stain, many types of species

Candidiasis - feed on glucose or serum, usually caused by Candida albicans

Tinea (pityriasis) versicolor - food source is follicular lipids. Malassezia furfur (Pityrosporum orbiculare)

Question 14

For impetigo, recognize the clinical characteristics and identify the etiologic agent.

Answer 14

Impetigo - v common in children, person-2-person, Two main types

Bacteriology
A. β-hemolytic streptococci (Streptococcus pyogenes)- non-bullous impetigo of children

B. Staphylococcus aureus- associated with both non-bullous and bullous impetigo (most common cause of both types of impetigo)

Non-bullous looks yellow, honey like

Question 15

Defensins are ________

Answer 15

small, cationic, cysteine-rich peptides that differ in their disulfide-bond pairing and tissue distribution.

Question 16

In general the normal flora grows best at an _______ pH while many pathogenic bacteria such as Staphylococcus aureus grow best at a ______ pH that is primarily maintained in the skin by lipids and sodium- proton exchange.

Answer 16

acidic, neutral

Question 17

For cellulitis ‐ recognize the clinical characteristics and identify the etiologic agent.

Answer 17

More common in the very young, elderly patients, immunocompromised patients, intravenous drug users, and in patients with chronic ulcers

Bacteriology
A. Erysipelas (clinical variant of cellulitis)- most commonly associated with β- hemolytic streptococci (Streptococcus pyogenes) - usually on face

B. Cellulitis- most commonly associated β-hemolytic streptococci (Streptococcus pyogenes), Staphylococcus aureus, and Haemophilus influenzae (in children) 1. Less common species include other groups of streptococci, Pneumococcus
species, Klebsiella species, Yersinia species, or even mixed gram-negative and gram-negative infections - usually on extremities