Mucocutaneous/Dermatopathology

Question 1

Lentigo

Solar vs Simple Lentigo

• Sun exposure
• Melanocyte proliferation
• Size

Answer 1

Solar Lentigo

• Sun exposure
• No melanocyte proliferation, just more melanin released
• Can be >10mm

Simple Lentigo

• Unrelated to sun exposure
• Melanocyte proliferation
• <5mm

Question 2

Melanocytic Nevus

• Age of appearance
• 3 subtypes of acquired
• Malignant potential

Answer 2

Congenital

• Present at birth
• No malignant potential (except really large lesions)

Acquired

• Superficial (flat), Dermal (dome shaped), Compound (uniformly raised)
  *

Question 3

Seborrheic Nevus

• Age of appearance
• Malignant potential
• Sudden appearance of hundreds of lesions ominous of what

Answer 3

• 4th decade and later
• No malignant potential
• Sudden appearance of hundreds of lesions (Lesser-Trelat Sign) ominous for internal malignancy

Question 4

Actinic Keratosis

• Locations
• Appearance
• Histology
• Malignant potential
• Treatment

Answer 4

• Sun exposed areas
• Rough, erythematous papules with white/yellow scales
• Atypical keratinocytes
• Malignant transformation 5-25% SCCa
• Topical chemo or cryosurgery
  
  • 5-FU
  • Imiquimod
  • Diclofenac

Question 5

Dysplastic Melanocytic Nevus

• Location
• Appearance
• Malignant potential
• Histo
• Tx

Answer 5

• Back and trunk
• Larger than common nevus, irregular borders, macular/papular
• Single lesion 2x risk of melanoma
• >10 lesions has 12x risk of melanoma
• Atypical melanocytes
• Excision 0.5mm margin

Question 6

Basal Cell Carcinoma

• Mutation
• % of all skin cancers
• Age
• Risk factors

Answer 6

• PTCH gene
• 80% of all skin cancers
• 6-7 decades
• Fitzpatrick 1-3, arsenic, radiation, immunosupression, HPV

Question 7

SCCa

• Mutation
• % of all skin cancers
• Age
• Risk factors

Answer 7

• p53
• 10% of all skin cancers
• 6-7 decades
• Fitzpatrick 1-3, arsenic, radiation, immunosupression, HPV

Question 8

BCCa / SCCa clinical presentation

• BCCa nodular
• BCCa superficial
• BCCa morpheaform
• SCCa

Answer 8

BCCa / SCCa clinical presentation

• BCCa nodular = firm papule, central depression
• BCCa superficial = Erythema plaque, mostly trunk
• BCCa morpheaform = Looks like scar
• SCCa = Erythema nodule, indurated, ulcerated

Question 9

BCCa subtype incidence

Nodular

Superficial

Morpheaform

Others

Answer 9

80% Nodular

15% Superficial

5% Morpheaform

Others <1%

Question 10

BCCa / SCCa mets and tx

• Metastatic rate
• Treatment
• Prognosis

Answer 10

Metastatic

• BCCa 1%
• SCCa 5%

Treatment

• 4mm margin low risk
• >4mm margin low risk
• Essentially no margin with Mohs

Prognosis

• BCCa - good
• SCCa - good unless mets

Question 11

BCCa / SCCa recurrence

Recurrence rate and factors

Answer 11

BCCa

• Positive margin 40%
• Negative margin 14%

SCCa

• 8%

Any lesion >2cm, long duration, “H” portion of face

Question 12

Melanoma

• % of skin cancers
• Risk factors
• Clinical presentation (ABCDE)
• Early growth pattern
• Later growth pattern

Answer 12

• 4% of skin cancers
• Risk factors: Fitzpatrick 1-3, sun exposure
• Clinical presentation (ABCDE): Asymmetry, Border irregular, Color variation, Diameter >6mm, Evolution of mole color/size
• Early growth pattern: Radial
• Later growth pattern: Vertical

Question 13

Melanoma types

• Most common
• Occurs on palm/soles
• Least common, radial growth only, best prognosis
• Second most common, vertical growth only, Red-blue-black nodule that doesn’t follow ABCDE rule

Answer 13

Melanoma types

• Superficial = Most common
• Acral lentiginous = Occurs on palm/soles
• Lentigo Maligna = Least common, radial growth only, best prognosis
• Nodular = Second most common, vertical growth only, Red-blue-black nodule that doesn’t follow ABCDE rule

Question 14

Melanoma staging

Breslow

Clark

Answer 14

Breslow = depth in mm, stages 1-5

Clark = depth in skin layers, stage 1-5

Question 15

Melanoma treatment

• Margins based on depth/stage
• When is sentinal lymph node biopsy indicated?

Answer 15

Margins

• 1cm = 1mm depth
• 2cm = all others

Sentinal lymph node biopsy

• ulceration
• >1mm depth

Question 16

Keratoacanthoma

• Low grade variant of what skin cancer?
• Unique growth rate
• Clinical appearance

Answer 16

• Variant of SCCa, can progress to invasive SCCa
• Grows quickly (weeks)
• Red, dome, central keratin pit

Question 17

MOHS

• 4 stages
• Contraindications

Answer 17

4 stages

1. Surgical removal of tissue
2. Mapping/staining the specimen
3. Histologic interpretation
4. Further tissue removal/reconstruction

Contraindications

• small lesions <3cm or otherwise not involving cosmesis
• Malignant Melanoma

Question 18

BCCa tx and recurrence

Primary lesion

• Which treatment modality has highest recurrence?
• Lowest recurrence?

Recurrent lesion

• Highest recurrence
• Lowest recurrence

Answer 18

BCCa tx and recurrence

Primary lesion

• Surgical excision = highest recurrence 10%
• MOHS = Lowest recurrence 1%

Recurrent lesion

• Radiation or Electrodissection/curretage = Highest recurrence 40-60%
• MOHS = Lowest recurrence 5%