Synopsis
Distinguish cutaneous squamous-cell carcinoma from basal-cell carcinoma, identify high-risk anatomy and pathology, obtain adequate tissue and select standard excision, Mohs surgery, field treatment, nodal care and advanced systemic therapy.
- BCC typically appears as a pearly telangiectatic papule, rolled-edge ulcer or scar-like plaque and is locally destructive but almost never metastasises.
- cSCC commonly appears as a tender indurated keratotic or ulcerated lesion that grows over weeks or months and can spread to regional nodes.
- First-line assessment includes full-skin and regional-node examination with dermoscopy and measurement; photograph site and size before biopsy.
- The diagnostic reference standard is representative full-thickness biopsy or excision that permits invasive depth, differentiation, subtype and perineural and lymphovascular assessment.
- High-risk cSCC features include ear or lip site, large diameter, depth beyond subcutaneous fat or over 6 mm, poor differentiation, perineural invasion, recurrence and immune suppression.
- First-line treatment for most invasive BCC and cSCC is complete surgical excision with a clinically appropriate margin and pathological confirmation.
- Mohs micrographic surgery is preferred for selected high-risk, recurrent, poorly defined or tissue-critical facial tumours because it examines the complete peripheral and deep margin while conserving tissue.
- Curettage, cryotherapy, photodynamic therapy, topical imiquimod or fluorouracil are reserved for carefully selected superficial low-risk lesions and must not be used for suspected invasive high-risk cSCC.
- A high-risk cSCC requires nodal examination at every review and ultrasound with FNA or core of a suspicious node; routine sentinel-node biopsy remains selective rather than standard for all.
- Named-nerve symptoms require contrast MRI for perineural spread and combined surgical and radiation planning.
- Locally advanced cSCC not suitable for curative surgery or radiotherapy may receive PD-1 blockade such as cemiplimab; advanced BCC can receive hedgehog-pathway treatment.
- Transplant recipients need expedited treatment, regular field surveillance and transplant-team review of immune suppression rather than uncoordinated drug reduction.
- Prevention combines shade, clothing, sunscreen, avoidance of tanning devices and surveillance without promoting complete sun avoidance or vitamin-D deficiency.
Key red flags
A rapidly enlarging tender keratotic nodule, indurated ulcer or non-healing lesion, especially on ear or lip, requires urgent SCC assessment.
Facial numbness, pain, weakness, formication or motor deficit suggests perineural spread and requires urgent MRI and specialist treatment.
A recurrent, poorly defined, morpheaform or infiltrative lesion on nose, eyelid, ear or lip needs margin-controlled surgical planning.
A hard parotid, cervical or other regional node in a patient with cSCC can be metastatic and requires imaging and tissue.
Transplant recipients and other immunosuppressed patients can develop multiple aggressive cSCCs with faster nodal spread.
Bleeding, deep fixation, bone exposure, orbital symptoms or a chronic ulcer arising in scar or radiation field suggests advanced high-risk disease.
New pain, tingling, numbness, facial weakness or formication along a nerve is a high-risk neurological sign.
Investigation priorities
Assess lesion pattern, margin, size, fixation and field damage and examine regional nodes and the remaining skin.
Management branches
A non-healing, enlarging, ulcerated, keratotic, pearly or scar-like lesion is clinically suspicious.
- Assess growth, pain, immune suppression, previous cancer and neural symptoms and perform dermoscopic full-skin and nodal examination with measurement and photograph.
- Obtain full-thickness excision or incisional biopsy from the most representative deep area, avoiding destructive treatment before invasive risk is known.
- Review pathology against the clinical border and refer high-risk site, subtype, depth, recurrence or immune context to the specialist skin-cancer MDT.