Bullous Disease and Cutaneous Neoplasms

Question 1

Describe the pathophysiology of dermatitis herpetiformis

Answer 1

IgA autoantibodies bind to the basement membrane, causing subepidermal bulla. Associated with coeliac disease

Question 2

Describe the clinical features of dermatitis herpetiformis

Answer 2

Itchy vesicles on the extensor surfaces of the elbows and the buttocks

Question 3

Describe the histological features of dermatitis herpetiformis

Answer 3

Microabscesses which coalesce to form subepidermal bullae. Neutrophil and IgA deposits at the tips of dermal papillae

Question 4

Describe the pathophysiology of pemphigoid

Answer 4

IgG antibodies bind to hemidesmosomes of the basement membrane, causing subepidermal (deep) bulla

Question 5

Describe the pathophysiology of pemphigus

Answer 5

IgG antibodies bind to desmosomal proteins, causing intraepidermal (superficial) bulla

Question 6

Describe the clinical features of pemphigoid

Answer 6

Large tense bullae on erythematous base. Often on the forearms, groin, and axillae. Usually an elderly patient

Question 7

Describe the clinical features of pemphigus

Answer 7

Easily ruptured bullae on the skin and mucosal membranes

Question 8

Describe the histological features of pemphigoid

Answer 8

Subepidermal bullae with eosinophils. Linear deposition of IgG along the basement membrane

Question 9

Describe the histological features of pemphigus

Answer 9

Intraepidermal bullae. Netlike pattern of intercellular IgG deposits. Acantholysis

Question 10

Describe the features of seborrhoeic keratosis

Answer 10

Rough plaques, waxy, stuck on appearance, affecting middle aged and elderly

Question 11

Name three premalignant cutaneous neoplasms

Answer 11

Actinic keratosis, keratoacanthoma, Bowen’s disease

Question 12

Name one benign cutaneous neoplasm

Answer 12

Seborrhoeic keratosis

Question 13

Describe the features of actinic keratosis

Answer 13

Rough, sandpaper like, scaly lesions on sun-exposed areas

Question 14

Describe the features of keratoacanthoma

Answer 14

Rapidly growing dome shaped nodule which may develop a necrotic, crusted centre. Grows over 2-3 weeks then clears spontaneously

Question 15

Describe the features of Bowen’s disease

Answer 15

Intra-epithelial squamous cell carcinoma in situ - flat, red, scaly patches on sun-exposed areas

Question 16

Describe the histological features of actinic keratosis

Answer 16

SPAIN: Solar elastosis, Parakeratosis, Atypia (dysplasia), Inflammation, Not full thickness

Question 17

Describe the histological features of Bowen’s disease

Answer 17

Full thickness dysplasia with an intact basement membrane

Question 18

Describe the histological features of squamous cell carcinoma

Answer 18

Full thickness dysplasia of epidermis, nuclear crowding, spreading through basement membrane into dermis

Question 19

Describe the histological features of basal cell carcinoma

Answer 19

Mass of basal cells pushing down into dermis, palisading (nuclei align in outermost layer)

Question 20

Describe the clinical features of basal cell carcinoma

Answer 20

Rodent ulcer - slow growing tumour with pearly surface and telangiectasia

Question 21

Name 3 types of melanocytic naevi

Answer 21

Junctional, compound, intradermal

Question 22

Describe the histology of malignant melanoma

Answer 22

Atypical melanocytes, initially growing horizontally in the epidermis (radial growth phase), then vertically into dermis (vertical growth phase) producing a buckshot appearance from Pagetoid cells

Question 23

Name the most important prognostic factor in malignant melanoma

Answer 23

Breslow thickness

Question 24

Name at least 3 subtypes of malignant melanoma

Answer 24

Lentigo, superficial spreading, nodular, acral lentiginous

Question 25

Which type of melanoma occurs on the palms, soles, and subungal areas?

Answer 25

Acral lentiginous

Question 26

Which type of melanoma occurs on the sun-exposed areas of elderly Caucasians as a flat, slow-growing black lesion?

Answer 26

Lentigo

Question 27

Which type of melanoma has irregular borders with variation in colour?

Answer 27

Superficial spreading

Question 28

Which type of melanoma is more common in younger people?

Answer 28

Nodular