Basal vs Squamous Cell Carcinoma: How They Differ and What Comes Next

Part of: Skin cancer & dermatologic surgery

Basal and squamous cell cancer: symptoms, excision, Mohs surgery and follow-up after treatment.

Skin cancer · 2 min read · September 10, 2026

Written and medically reviewed by Dr. Yousef Abo Zarad · German board-certified dermatologist · Last reviewed: September 2026

The short answer

Basal cell carcinoma (BCC) is the most common skin cancer. It grows slowly and rarely spreads, but it can grow deep if neglected.1 Squamous cell carcinoma (SCC) is highly curable when found early, but can occasionally spread to lymph nodes and other organs.2

A suspicious lesion needs clinical evaluation and an appropriate biopsy for diagnosis, followed by assessment of tumour risk, site and depth. Surgery remains the cornerstone for most cases; creams or radiation are not automatically interchangeable alternatives.45

What does each look like?

  • BCC: a firm, round, raised growth (the most common form), a circle that dips in the centre, a scaly patch, a sore that does not heal or heals and returns, a scar-like mark, or a cluster of shiny bumps.1
  • SCC: a rough, scaly patch, a firm dome-shaped growth with a raised border, a non-healing sore, a wart-like or horn-like growth, or a changed scar.2
  • Colour: red or pink on lighter skin, and brown, black or grey-blue on darker skin.12
  • Symptoms: there may be itching, pain or tingling, or none at all.2
  • Photos are not enough: appearance alone cannot confirm the diagnosis.

Who is most at risk of squamous cell carcinoma?

  • Frequent unprotected sun exposure, and indoor tanning.2
  • Light skin, light eyes, red or blond hair, and repeated sunburns.2
  • Solid-organ transplant, actinic keratosis, a previous skin cancer, and old scars or long-lasting wounds.2
  • It is the most common skin cancer in people with darker skin.2

What is the treatment?

  • Surgical excision: removes the tumour with appropriate margins and histopathology, and is the mainstay for many patients.45
  • Mohs surgery: assesses tumour margins during surgery while sparing healthy tissue, especially at critical sites or for recurrent/high-risk lesions.45
  • Curettage and electrodesiccation: may be used for selected superficial, small low-risk tumours.45
  • Topicals such as imiquimod or 5-FU: may treat selected superficial BCC, not every tumour and not invasive squamous cell carcinoma.4
  • Radiotherapy or systemic drugs: considered when surgery is unsuitable or disease is advanced, depending on histology and risk.45

Does microscope-controlled surgery change the chance of recurrence?

Mohs or conventional excision is chosen by tumour site, size, risk and the need for precise margin assessment. Recurrence studies are informative, but a single pooled number cannot predict an individual patient's result because tumour types, sites and patient risk differ. Complete treatment with an appropriate approach matters most.345

What to do after treatment

  • Ongoing checks: AAD clinical guidelines recommend at least annual skin examination following BCC or SCC; higher-risk cases may need closer surveillance.45
  • Self-checks: monitor for new lesions or changes at the scar and do not wait for a routine appointment when concerned.12
  • Prevention: sun protection and avoiding tanning beds reduce further UV damage.12

When should you see a dermatologist?

  • A spot or growth that grows, bleeds, does not heal or changes in any way.1
  • A growth, bleeding or foul smell in a scar, wound or old sore: straight away.2
  • After treatment: a new lump, bump or sore near the scar, or a swollen lymph node.2

Medical Evidence