Chapter 18 - Plastics

Question 1

What are the main types of cells in the epidermis

Answer 1

Keratinocytes. Originate from basal layer; provide mechanical barrier

Question 2

Where do the melanocytes originate from?

Answer 2

Neuroectodermal origin; in basal layer of epidermis.

Have dendritic processes that transfer melanin to neighboring keratinocytes via melanosomes

Question 3

What are langerhan cells, and where are they?

Answer 3

in the dermis. Act as antigen presenting cells. They originate from bone marrow. They have a role in contact hypersensitivity reactions (type IV)

Question 4

These are pressure sensory nerves

Answer 4

Pacinian corpuscles

Question 5

What are the warmth sensory nerves

Answer 5

Ruffini’s endings

Question 6

What are the cold sensory nerves?

Answer 6

Krause’s and bulbs

Question 7

What are the tactile sensation sensory nerves?

Answer 7

Meissner’s corpuscles

Question 8

What do Eccrine sweat glands do?

Answer 8

• Produce aqueous sweat
• Used for thermal regulation
• Usually produce hypotonic sweat

Question 9

What do apocrine sweat glands do?

Answer 9

• Produce milky sweat
• Highest concentration of glands in palms and soles
• Most sweat is the result of sympathetic nervous system via acetylcholine

Question 10

What is the most predominant type of collagen in the dermis?

Answer 10

Type one collagen. 70% of the weight of dermis; gives tensile strength

Question 11

What are Cushing’s striae caused by?

Answer 11

Loss of tensile strength and elasticity

Question 12

What is the donor site of a split thickness skin graft regenerated from?

Answer 12

Hair follicles and skin edges

Question 13

How is a split thickness skin graft supported for the first three days

Answer 13

imbibition, osmotic blood supply

Question 14

When does neovascularization of a split thickness skin graft begin?

Answer 14

Starts at day three. Tendon, bone without periosteum, XRT areas are unlikely to support graft

Question 15

What is the most common cause of pedicled or free flap necrosis?

Answer 15

Venous thrombosis

Question 16

What are the complications of a tram flap?

Answer 16

Flap necrosis, ventral hernia, bleeding, infection, abdominal wall weakness

Question 17

How does UV radiation cause damage?

Answer 17

• Damages DNA and repair mechanisms
• It is both a promoter and an initiator
• Melanin is the single best factor for protecting skin from UV radiation
• UVB is responsible for chronic sun damage

Question 18

What percentage of skin cancers melanoma?

Answer 18

3 to 5% of skin cancer but accounts for 65% of deaths

Question 19

What are some genetic risk factors for melanoma?

Answer 19

Dysplastic, atypical, or large congenital nevi - 10% lifetime risk for melanoma

Familial BK mole syndrome - almost 100% risk of melanoma

Xeroderma pigmentosum

Question 20

What percentage of melanomas are familial?

Answer 20

10%

Question 21

What is the most common melanoma site on skin?

Answer 21

Back in men, legs in women

Question 22

What are signs of poor prognosis in melanoma

Answer 22

Color change, angulation, indentation/notching, enlargement, darkening, bleeding, ulceration

Question 23

How do you go about diagnosing suspicious lesions for melanoma?

Answer 23

• Less than 2 cm lesion (or core needle) - excisional biopsy unless a cosmetically sensitive area
• Greater than 2 cm lesions or cosmetically sensitive areas - incisional biopsy (or punch)
• Need resection with margins if pathology comes back Melanoma

Question 24

What is lentigo maligna melanoma? Is it aggressive? How does it behave?

Answer 24

• Least aggressive melanoma, minimal invasion, radial growth first
• Elevated nodules

Question 25

What is superficial spreading melanoma?

Answer 25

Most common, intermediate malignancy; originates from Nevus/sun exposed areas

Question 26

What is nodular melanoma?

Answer 26

Most aggressive; most likely to have metastasized at time of diagnosis; Deepest growth at time of diagnosis; vertical growth first; bluish black with smooth borders; occurs anywhere on the body

Question 27

What is accral lentiginous melanoma?

Answer 27

Very aggressive; palms/soles of African-Americans

Question 28

What do you do with melanoma in situ or thin lentigo maligna?

Answer 28

0.5 cm margins okay

Question 29

What do you do with nodes in melanoma?

Answer 29

* Always resect clinically positive nodes in melanoma * Perform SLNBx if nodes clinically negative and tumor greater than 1 mm deep * Involved nodes often nontender, round, hard, 1.5 cm * Need to include superficial parotidectomy for anterior head and neck melanomas

Question 30

What do you do with axillary node melanoma with no other primary?

Answer 30

Complete axillary node dissection

Question 31

Do you resect the metastases of melanoma?

Answer 31

Yes, can provide some patients with long disease free interval and is best chance for cure

Question 32

Basal cell carcinoma? * epidemiology * location * appearance * path

Answer 32

* Most common malignancy in US; 4X more common than squamous cell carcinoma * 80% on Head/neck * Pearly appearance, rolled borders * Pathology shows peripheral palisading of nuclei and stromal retraction * Morpheaform type most aggressive; has collagenase production

Question 33

Squamous cell carcinoma? Appearance? More/less frequent metastasis?

Answer 33

* Overlying erythema * Papulonodular w/ crust and ulceration * Usually red-brown; can also be Pearly * Metastasize more frequently than basal cell carcinoma but less than melanoma

Question 34

What are some characteristics of soft tissue sarcoma?

Answer 34

* Most common soft tissue sarcoma: malignant fibrous histiosarcoma, then liposarcoma * 50% extremities * 50% in children (from embryonic mesoderm) * Present with asymptomatic mass, G.I. bleeding, bowel obstruction, neurologic deficit * Need CXR to rule out lung mets * MRI to rule out vascular, neuro, bone invasion (before biopsy) * Biopsy

Question 35

How do you biopsy soft tissue sarcoma?

Answer 35

* Core needle biopsy is best * Excisional biopsy if mass \< 4 cm * Longitudinal incision biopsy for masses \> 4 cm * Hematogenous spread, not to lymphatics * Lung most common site for metastasis * Biopsy site must be excised if pathx is sarcoma

Question 36

How do you stage soft tissue sarcomas?

Answer 36

* Based on grade, not size or nodes * Grade is most important prognostic factor * Undifferentiated gives worst prognosis

Question 37

Characteristics of head and neck sarcomas?

Answer 37

* Can be in kids * Usually rhabdomyosarcoma * Hard to get negative margins

Question 38

What is the most common pathx of visceral and retroperitoneal sarcomas? What is the most important prognostic factor?

Answer 38

* Most commonly leiomyosarcoma and liposarcomas * Ability to completely remove the tumor is the most important prognostic factor

Question 39

PVC and arsenic exposure increase risk for what?

Answer 39

Angiosarcoma

Question 40

Chronic lymphedema is associated with what sarcoma?

Answer 40

Lymphangiosarcoma

Question 41

What is Kaposi's sarcoma?

Answer 41

* Vascular sarcoma * Can involve skin, mucous membranes, G.I. tract * Treat with XRT or intralesional vinblastine

Question 42

Childhood rhabdomyosarcoma?

Answer 42

* Number one soft tissue sarcoma in kids * Head/neck, GU, ext, trunk (worst prognosis) * Embryonal subtype is most common * Alveolar subtype worse prognosis * Surgery; doxorubicin-based chemotherapy

Question 43

Bone sarcoma characteristics?

Answer 43

* Most are metastatic at diagnosis * Osteosarcoma-increased incidence around the knee, originates from metaphyseal cells * Need to take the joint followed by reconstruction

Question 44

What soft tissue tumors are caused by neurofibromatosis?

Answer 44

* CNS tumors * Peripheral sheath tumors * Pheochromocytoma

Question 45

What soft tissue tumors are caused by Li-fraumeni syndrome?

Answer 45

Childhood rhabdomyosarcoma and many others

Question 46

What soft tissue tumors are caused by tuberous sclerosis?

Answer 46

Angiomyolipoma

Question 47

What do xanthomas look like, what do they contain, how do you treat them?

Answer 47

Yellow in appearance, contain histiocytes, excise

Question 48

What is actinic keratosis?

Answer 48

Premalignant, found in sun damaged areas; need excisional biopsy if suspicious

Question 49

What is arsenical keratosis associated with?

Answer 49

squamous cell carcinoma

Question 50

What are Merkel cell carcinomas?

Answer 50

* Neuroendocrine in nature * Aggressive * Red to purple papular nodule and indurated plaque * Have neuron specific in enolase, cytokeratin, and neurofilament protein

Question 51

What is a glomus cell tumor?

Answer 51

Painful tumor composed of blood vessels and nerves Benign, most common in the terminal aspect of the digit

Question 52

What is a Hutchinsons freckle?

Answer 52

Found in the elderly on the face, premalignant, not aggressive

Question 53

What are desmoid tumors?

Answer 53

* Usually benign; occur in facial planes * Anterior abdominal wall can occur during or after pregnancy, trauma, or surgery * Intra-abdominal associated with Gardner syndrome and retroperitoneal fibrosis

Question 54

What is the most common location for melanoma metastasis?

Answer 54

Lung

Question 55

SCC management of high risk lesions (large, poorly differentiated, perineural differentiation)? Alternative treatments?

Answer 55

Surgical excision. If do not wish surgery or poor candidate - cryotherapy, electrosurgery, radiation therapy.

Question 56

What do melanomas stain for on pathology?

Answer 56

S-100 and HMB-45 proteins

Question 57

How do you treat soft tissue sarcomas?

Answer 57

* Resect w/ 2-3 margins & 1 uninvolved fascial plane * Postop XRT for high grade, close margins, \>5 cm * Chemotherapy is doxorubicin-based (Adriamycin) * If \>10 cm, preop chemo-XRT may be limb-sparing * Resect isolated metastasis without evidence of systemic disease * Poor prognosis, 40% five-year survival rate with complete resection