<![CDATA[Mock34 Malignant Melanoma]]>Stem
33-year-old man referred to outpatient clinic by his GP following a skin biopsy of forearm lesion. His report reads: skin biopsy shows epidermis and dermis in which there is proliferation of atypical non-pigmented epithelioid melanocytes at the junction and invading the dermis up to the deep margin, the features of those malignant melanoma.

What is the basic difference between melanoma and SCC?

Melanoma
Tumour of melanocytes
Arise from the lower layer of the epidermis
SCC
Epithelial cells
Arise from upper and mid-layer of epidermis

What treatment is indicated as consequences of pathology report?

Do further surgery to achieve complete resection.

Describe 3 histopathological features of invading melanoma that indicate an aggressive potential of melanoma and likely poor prognosis?

Increased tumour thickness (Breslow thickness)
Increased depth of invasion (deep dermal or subcuticular tissue invasion).
Presence of lymphatic, blood vessels or perineural invasion.
Presence of ulceration.

What is a satellite lesion?

Focus of melanoma separate from the main tumour mass usually visible on the skin surface, it usually arises as a result of lymphatic spread and growth of tumour embolus locally

What pathological features can be regarded as good prognostic features from histology report?

Limited tumour depth of invasion.
No lymphocytic infiltration.

Why sun exposure is a risk factor for malignant melanoma?

High energy radiation in the ultraviolet → can damage DNA → causing mutations

Name 2 inherited condition with increased risk of malignant melanoma?

Xeroderma pigmentosa
Dysplastic naevus syndrome.

The pt undergo a complete excision of 1mm thick melanoma with clear margins about 0.5mm, what is likely next step in treatment?

Wider excision with additional boundaries to be determined by Breslow thickness of melanoma.

What intra-operative investigation can assist you to provide a comment that the margin is clear?

Frozen section.
Mohs micrographic surgery.
The patient is seen again in clinic after 18 months with painless swelling in the axilla.

What simple pathology in the clinic test can often confirm that is likely metastatic disease?

FNAC

When considering additional cancer therapy, what gene mutation is commonly tested in such cases?

BRAF gene

Post excision of axillary lymph nodes, the patient developed painful swelling of the arm and distal oedema cause?

Axillary vein thrombosis

Give two risk factors of thrombosis in this patient?

Surgery to metastatic melanoma with local tissue injury will increase the local thrombotic tendency.
Altered blood flow at the site of tissue injury.

How can you know the phenotype of the tumour?

Immunohistochemistry

Where would you examine this lady?

Primary sites: whole lower limb including nail beds and soles.
Metastatic sites: chest, abdomen and brain.

How would you treat this lady?

Excision of the primary lesion with safety margin.
Block inguinal lymph node dissection
Radiotherapy

What is SIRS?

Systemic Inflammatory Response Syndrome.
Manifestations of SIRS include, two or more of the following:
Body temperature
< 36°C
or > 38°C
Heart rate > 90 bpm
White blood cell count
< 4000 cells/mm³
or > 12,000 cells/mm³
or the presence of greater than 10% immature neutrophils.
Respiratory rate
20 breaths per minute
or, an arterial partial pressure of carbon dioxide less than 4.3 kPa (32 mm Hg).

What happens to lung in SIRS?

ARDS

]]>https://isurg.org/topic/469/mock34-malignant-melanomaRSS for NodeWed, 22 Jul 2026 21:39:42 GMTSat, 18 Jul 2026 14:11:51 GMT60<![CDATA[Reply to Mock34 Malignant Melanoma on Wed, 22 Jul 2026 10:37:33 GMT]]>Stem2: A patient known to have hypothyroidism with a hard swelling in the inguinal region, the GP sent her for a biopsy.

If the inguinal LNS was lymphoma what are the distinct types of lymphoma?

Hodgkin
Non-Hodgkin

How malignant cells survive in LNSs

Malignant tumours release growth factors such as VEGF-C (vascular endothelial growth factor C) to induce lymphatic vessel expansion (lymph angiogenesis) in primary tumours and in draining sentinel LNs, thereby promoting LN metastasis

Why is melanoma pigmented?

Because of melanin

Mention 4 types of melanoma?

Lentigo maligna
Superficial spreading
Desmoplastic melanoma
Acral melanoma
Nodular melanomas

A lesion under the toenail was found and the decision to amputate the toe and excise the LNs.
What is the reason behind this decision?

To prevent metastasis
Safety margin
Pain control

What is epithelioid melanoma?

Type of melanoma with cells resembling epithelium because of
Abundant eosinophilic cytoplasm
Enlarged round to oval shaped nuclei.

Gene mutation in familial malignant melanoma?

BRAF gene

Postoperatively the wound is red and swollen. Culture revealed diplococci give examples?

Gram-negative diplococci
Neisseria sp.
Haemophilus
Brucella
Moraxella catarrhalis
Acinetobacter

Gram-positive diplococci

Streptococcus pneumoniae
Enterococcus.

Next the patient became toxic with rapid spread of infection what do you think the cause?

Necrotizing fasciitis

]]>https://isurg.org/post/697https://isurg.org/post/697Wed, 22 Jul 2026 10:37:33 GMT