Dermatology Book

http://www.fpnotebook.com/

Basal Cell Carcinoma

Aka: Basal Cell Carcinoma, Basal Cell Cancer
Advertisement
  1. See Also
    1. Nonmelanoma Skin Cancer
    2. Basal Cell Nevus Syndrome
  2. Epidemiology
    1. Most common cutaneous malignancy
    2. Incidence (1998, US): 400,000-500,000 per year
    3. Occurs in under age 50 years in 20% of cases
  3. Pathophysiology
    1. Derived from Basal Cell Layer of Keratinocytes
      1. Deepest cell layer of Epidermis
      2. Cells are Basophilic with large nuclei
    2. BCC requires stroma to support growth
      1. Makes metastasis improbable
  4. Signs
    1. Distribution
      1. Chronic sun exposed areas (head and neck) account for 85% of lesions
        1. Nose accounts for 25% of cases
      2. Minimally sun exposed areas account for as many as 33% of Basal Cell Carcinoma cases
    2. Characteristics: Nodular
      1. "Pearly" or translucent dome-shaped Papule
      2. Overlying telangiectases (develop with growth)
      3. Waxy or translucent surface
      4. Central Ulceration
      5. Raised, rolled border
      6. Friable, non-healing lesions that bleed frequently
    3. Atypical presentations
      1. Pigmented Basal Cell Carcinoma (uncommon)
        1. Contains Melanin with a resulting blue, brown or black coloration
        2. Differentiate from Melanoma
  5. Diagnosis: Skin Biopsy
    1. Raised lesion: Shave Biopsy if not pigmented
      1. Any suspicion of Melanoma needs full-thickness sample
    2. Flat lesions: Punch Biopsy or full excision
  6. Types (mixed types in 40% of cases)
    1. Nodular lesions
      1. Nodular Basal Cell Carcinoma (21%)
      2. Variants with higher invasive potential
        1. Micronodular Basal Cell Carcinoma(15%)
        2. Infiltrative Basal Cell Carcinoma(7%)
    2. Other forms
      1. Superficial Basal Cell Carcinoma (17%)
        1. Localized to trunk and extremities
        2. Scaly Plaque (similar to eczema or Psoriasis)
        3. Raised pearly white borders (similar to nodular type)
        4. Least invasive BCC subtype
      2. Morpheaform Basal Cell Carcinoma (1%)
        1. Firm, yellow, ill-defined lesion (similar to Scleroderma)
        2. Carcinoma borders often extend beyond what is visible on exam
        3. Higher invasive potential
  7. Management
    1. Electrodesiccation and curettage (ED&C)
      1. Indications
        1. Intermediate size lesions
        2. Maintains dermal integrity with minimal scar
        3. More difficult if prior Punch Biopsy
      2. Technique
        1. Scrape with curette
        2. Electrodessication to base with radiofrequency
        3. Repeat "scrape and burn" 3 times
        4. Send first curettage sample to pathology
        5. Keep area moist afterward (e.g. Bacitracin)
      3. Recurrence rate
        1. Low-risk site: 8.6%
        2. High-risk site: 17.5%
    2. Full thickness excisional surgery
      1. Indications
        1. Deeper, diffuse or more advanced lesions
        2. Basosquamous carcinoma
    3. Cryotherapy
      1. Indications
        1. Superficial BCC or Nodular BCC with depth <3 mm
        2. Requires biopsy first to check depth
      2. Recurrence rate: 3.5 to 16.5% depending on size and location
    4. Topical therapy
      1. Indications
        1. Must be a non-aggressive, superficial BCC only
        2. Small tumors in low risk locations and patient unwilling to undergo other more effective therapies
      2. Therapies
        1. Topical 5-Fluorouracil (Efudex)
        2. Topical Imiquimod 5% daily for 7 weeks
        3. PDT with 5-aminolevulinic acid
      3. References
        1. Geisse (2004) J Am Acad Dermatol 50:722-33
    5. Mohs' Micrographic Surgery
      1. Efficacy
        1. Maximum cure rates (99% at 5 years)
        2. Maximum normal tissue preservation
      2. Indications
        1. Recurrent Basal Cell Carcinoma
        2. Primary basal cell lesions with invasive subtypes (Micronodular, Infiltrative, Morpheaform)
        3. Positive biopsy margins (see below)
        4. Large tumors (>2 cm)
        5. Tumors in the H-Region of the face (Nose, Eyelids, chin, jaw, ear)
    6. Large, advanced growths
      1. Radiation Therapy
      2. Chemotherapy
  8. Management: Positive biopsy margins (incomplete excision)
    1. Seen with Shave Biopsy or Punch Biopsy
      1. Re-excision often yields negative sample
      2. Yet high rate of recurrence
    2. Most recommend Mohs Micrographic Surgery
      1. Berlin (2002) J Am Acad Dermatol 46(4):549-53
      2. Bieley (1992) J Am Acad Dermatol 26:754-6
      3. Holmkvist (1999) J Am Acad Dermatol 41(4):600-5
    3. Observing low-risk sites may be acceptable
      1. Less than 1 cm diameter lesions
      2. Not located on nose or ears
      3. Marginal involement of 4% or less
  9. Course
    1. Slow growing tumors
    2. Rarely metastasize
    3. Locally Invasive!
    4. Histologic characteristics for local extensive spread
      1. Sclerosing pattern (tumor strands in fibrous stroma)
      2. Perineural or perivascular invasion
      3. Focal areas of squamous differentiation
    5. Clinical characteristics for local extensive spread
      1. Basal Cell Carcinoma on nose
      2. Morpheaform Basal Cell Carcinoma on cheek
      3. Basal Cell Carcinoma involving neck
      4. Recurrent Basal Cell Carcinoma in men
      5. Basal Cell Carcinoma involving Eyelid, temple, or ear
      6. Basal Cell Carcinoma lesions >10 mm in diameter
      7. Batra (2002) Dermatol Surg 28:107-12
  10. Resources
    1. Basal Cell Carcinoma Nevus Syndrome Support Network
      1. http://www.bccns.org
  11. Prevention
    1. See Nonmelanoma Skin Cancer
    2. See Sun Exposure (lists general preventive measures)
    3. See Sunscreen
  12. References
    1. Habif (2004) Dermatology p. 724-35
    2. Firnhaber (2012) Am Fam Physician 86(2): 161-8
    3. Stulberg (2004) Am Fam Physician 70:1481-8

Navigation Tree