Skin Cancers (SCC, BCC, malignant Melanomas) & Benign Pigmented Skin Lesions Flashcards
Describe the pathophysiology of basal cell carcinoma. What are the cellular and molecular mechanisms involved?
The pathogenesis of BCC involves the activation of the Hedgehog signaling pathway (often due to PTCH1 gene), which is crucial in regulating cell growth and differentiation during embryonic development. In adulthood, dysregulation causes uncontrolled cell proliferation seen in BCC.
What genetic mutations are most commonly associated with basal cell carcinoma?
Mutations, particularly in the PTCH1 gene, lead to uncontrolled cellular proliferation. This results in the formation of a tumor that can invade surrounding tissues.
What are the primary risk factors for developing basal cell carcinoma?
- UV exposure
- skin type
- genetic (syndromes and family history)
- immunosuppression
How would you describe the most common type of basal cell carcinoma? (Nodular BCC)
Pearly, translucent nodule with telangiectasia, rolled edges and ulceration, often on the face.
How would you diagnose a BCC?
- clinical examination with dermoscopy
- biopsy for histopathology if needed.
What are the main treatment options for basal cell carcinoma? Which one is first line?
Depends on size, location and subtype. Surgical excision is first line.
- Topical treatment (e.g. imiquimod, 5-fluorouracil)
- Surgical excision/ Mohs micrographic surgery
- Radiotherapy if aggressive.
What is the prognosis for patients diagnosed with basal cell carcinoma? What are 2 main complications with BCCs?
Generally excellent. It rarely metastasises.
The main risk if local destruction to structures and the future risk of developing skin cancers.
How would you manage a patient with a basal cell carcinoma located on the nose versus one located on the trunk?
BCC on the nose, a high-risk area, may require Mohs micrographic surgery for tissue-sparing excision and high cure rates. BCC on the trunk can often be managed with simpler excisional surgery or other treatments like cryotherapy, depending on the size and depth.
What is the most common type of skin cancer in the UK?
Basal Cell Carcinoma (BCC)
It arises from the basal cells of the epidermis and rarely metastasizes. However, it can cause significant local destruction if left untreated.
What is the most common subtype of BCC?
Nodular BCC
Which type of BCC presents like a white, waxy scar, may be slightly depressed, and may be unrecognisable for a long time leading to an extensive disease requiring surgical excision?
Sclerosing/morpheaform BCC
Which type of BCC tends to affect the trunk and limbs? What is its presentation?
Superficial BCC. Look more like Scaly, erythematous patches, that may resemble psoriases or eczema, but in isolation.
How would you generally refer a patient with suspected BCC? What may be an exception?
General specialist clinic.
However, refer to a 2 week cancer wait if there is particular concern that a delay may have a significant impact, because of factors such as lesion site or size.
What is Mohs micrographic surgery? What are its indications?
Mohs Micrographic Surgery: Excision is done layer-by-layer and is immediately microscopically examined each layer is excised, this means that only only cancerous tissues are removed, whilst as much of the healthy tissue is preserved as possible.
This is done:
In areas where preserving as much of the area is important - for example near the eyes or on the lips
What are specific risk factors for melanomas compared to other skin cancers?
- Multiple moles or atypical moles
- genetic mutations e.g. BRAF gene, family history
