Mohs Micrographic Surgery and Cutaneous Oncology

Question 1

Mohs provides the highest cure rate for tumours that spread by direct extension.

Answer 1

T

Question 2

MOHs has clearance approx 80% for recurrence rate

Answer 2

F >90%

Question 3

Critical in the process is that the skin edge and deep surface are visualized in one plane on the glass slide, and thus the entire margin can be analysed

Answer 3

T

Question 4

Mohs surgery originally involved the use of zinc chloride (as a fixative), combined with stibnite (as permeant) and bloodroot powder (Sanguinaria Canadensis) (as agglutinant).

Answer 4

T This is the same as black salve!

Question 5

Conventional breadloaf sectioning of tumours allows for examination of 10% of the tumour’s margin.

Answer 5

F

Question 6

Indications for MOHs micrographic surgery includes tumour larger than 2cm in diameter

Answer 6

T

Question 7

Tumours of the skin of the upper lips are usually SCC, while those of the cutaneous lower lip are most commonly BCC.

Answer 7

F Other way round.

Question 8

Most Mohs laboratories use routine hematoxylin and eosin staining for all specimens.

Answer 8

T

Question 9

Technical errors are the most common cause of local recurrences after Mohs surgery.

Answer 9

T

Question 10

Large or thick tumours may be debulked using a curette as this may further delineate margins and reduce the number of layers necessary to obtain clear margins

Answer 10

T

Question 11

A saucer-shaped specimen with 45degree bevelled edges is ideal so that the specimen may be flattened

Answer 11

F 30 degrees. Flattening means that the bottom and margins can be sectioned by the Mohs technician in the same plane

Question 12

The specimen has its non-epidermal edges stained to allow proper orientation. At least four colours are used for each specimen to allow for adequate orientation

Answer 12

F Two to three colours

Question 13

In the laboratory, vertical sections are taken

Answer 13

F Specimen is placed bottom side up toward the microtome stage to allow horizontal sections

Question 14

The tissue may be immediately frozen with tetrafluoroethylchloride or liquid nitrogen and then transferred to the cryostat for thorough freezing

Answer 14

T

Question 15

Toluidine blue can be used for BCCs but has poor optical clarity

Answer 15

F Favoured by some for its optical clarity, but the process of immunostatins is impractical for routine use

Question 16

Infiltrative BCC is not distinctive clinically, but histologically contains islands of tumour cells with a spiked appearance in narrow cords within a hyalinised stroma

Answer 16

T

Question 17

BCCs with aggressive histology (ie. ulcerative, metatypical, morpheaform, infiltrative forms) require more Mohs layers to achieve tumour-free margins.

Answer 17

T

Question 18

BCC tumour size does not affect the extent of subclinical spread.

Answer 18

F

Question 19

Recurrent BCCs after radiotherapy often have morphoeaform or metatypical patterns.

Answer 19

T

Question 20

Metastatic BCC occurs in less than 0.5% of cases.

Answer 20

T

Question 21

Risk factors for metastatic BCC include tumour invasion into cartilage, bone, skeletal muscle or parotid gland, previous XRT and previous treatment with any modality.

Answer 21

T

Question 22

The nose is the most common site from which metastatic spread of BCC occurs.

Answer 22

F The ear.

Question 23

BCC metastasis occurs haematogenously only to lungs, bone&skin.

Answer 23

F Also through lymphatics.

Question 24

Biologically aggressive subtypes of SCC include cystic SCC, adenoid SCC, clear cell carcinoma and spindle cell carcinoma.

Answer 24

T

Question 25

SCCs arising in immunocompromised pts tend to be more aggressive and have higher metastatic rates.

Answer 25

T

Question 26

SCCs that are more likely to recur or metastasize should not be considered for Mohs.

Answer 26

F

Question 27

There is an increased risk for metastatic spread for SCCs that are histologically moderately to poorly differentiated, and for facial lesions, particularly temple, nose, lip, periocular, or periauricular.

Answer 27

T

Question 28

SCCs with perineural invasion do not have an increased risk of recurrence.

Answer 28

F

Question 29

Mohs for recurrent SCC can provide local cure rates of 94% or greater.

Answer 29

T

Question 30

For SCC the combination of chemotherapy agents cisplatin, 5-FU and bleomycin had an overall response rate of 79%

Answer 30

T

Question 31

For advanced head and neck SCC cetuximab, a monoclonal antibody inhibitor of epidermal growth factor receptor, has been shown to have effect

Answer 31

T

Question 32

Induction chemotherapy with docetaxel, cisplatin and flurorouracil offers increased median time survival for locally advanced SCC of head and neck when used alone

Answer 32

F When used with concurrent chemoradiotherapy

Question 33

Incidence of nodal mets greatly increases with Breslow depth

Answer 33

T Used for invasive melanomas intermediate in depth between 1 and 4mm

Question 34

Radiotherapy is the treatment of choice for verrucous carcinoma.

Answer 34

F Becomes more aggressive after XRT.

Question 35

Mohs micrographic surgery has been successfully used to treat Merkel cell carcinoma, a neuroendocrine tumour of the skin

Answer 35

T

Question 36

The pathogenesis of Merkel cell carcinoma is linked to a virus in some cases

Answer 36

T Merkel cell polymavirus

Question 37

Merkel cell carcinoma has local recurrence rates of 30%, regional node involvement rates of up to 50%, and metastatic rates of 40%.

Answer 37

T

Question 38

Survival rates for Merkel cell carcinoma statistically correlate with nodal status.

Answer 38

T

Question 39

A 2cm margin is recommended for primary excision of Merkel cell carcinoma.

Answer 39

F 3cm.

Question 40

Although the optimal treatment of Merkel cell carcinoma is unknown, radiation therapy is a commonly used adjunct to surgery to improve local control

Answer 40

T

Question 41

Adjunctive chemo for Merkel cell has been proven to improve survival

Answer 41

F No chemotherapy protocol has been shown to improve survival

Question 42

Adjuvant XRT is recommended for large, recurrent or incompletely excised Merkel cell carcinomas.

Answer 42

T

Question 43

Dermatofibrosarcoma protuberans is characteristically a rapid growing, locally aggressive malignant tumour of the skin

Answer 43

F A slow growing tumour

Question 44

Dermatofibrosarcoma protuberans is most common on the distal extremity.

Answer 44

F Trunk, upper thighs, groin.

Question 45

Recurrence rates after wide excision of DFSP can be as high as 60%.

Answer 45

T

Question 46

DFSP rarely metastasize.

Answer 46

T

Question 47

DFSP tumours over 2cm in dimaeter need a margin of 1.5cm

Answer 47

F 1.5cm margin for DFSP less than 2cm diameter Larger tumours – 2.5cm margin

Question 48

DFSP stains positively with CD34

Answer 48

T

Question 49

Atypical fibroxanthoma (AFX) usually presents as an ulcerated, erythematous nodule or plaque on heavily actinically damaged skin of the head and neck in older men

Answer 49

T

Question 50

Malignant fibrous histiocytoma has a worse prognosis than atypical fibroxanthoma.

Answer 50

T

Question 51

Malignant fibrous histiocytoma is a soft tissue sarcoma with a better prognosis with than AFX

Answer 51

F Less favourable

Question 52

In malignant fibrous histiocytoma special stains may be of value with CD74 positive in 90% of patients

Answer 52

T

Question 53

Microcystic adnexal carcinoma (MAC) occurs most commonly on the periorbital region of elderly men.

Answer 53

F Upper lip in middle-aged women.

Question 54

MAC frequently invade into skeletal muscle, and perineural invasion is often seen.

Answer 54

T

Question 55

Local recurrence rate for MAC excised with standard excision is 10%.

Answer 55

F Almost 50%. Mohs is 10%.

Question 56

Primary eccrine adenocarcinoma (eccrine porocarcinoma) is radioresistant.

Answer 56

T

Question 57

Sebaceous carcinoma most frequently occurs on the eyelids and has a tendency for local invasion and metastases

Answer 57

T

Question 58

Mohs micrographic surgery is not an appropriate management option for Merkel cell carcinoma

Answer 58

F - especially for early stage, face/ scalp + neck cases though not frequently (JAAD paper Jan 18)