Skin - Nonmelanocytic tumors
Carcinoma (non-adnexal)
Basal cell carcinoma (BCC)

Author: Ghassan Tranesh, M.D. (see Authors page)
Editor (personal): Hong Qu, M.D.
Editorial Board review: Sara C. Shalin, M.D., Ph.D.

Revised: 3 November 2016, last major update November 2016

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Basal cell carcinoma [title] skin

Cite this page: Basal cell carcinoma (BCC). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skintumornonmelanocyticbcc.html. Accessed December 9th, 2016.
Definition / General
  • BCC is most common malignancy of skin, constitutes ~80% of all skin cancers (eMedicine)
  • Patients with xeroderma pigmentosum, who have a diminished capability for repairing sun induced mutations, develop a large number of basal cell and squamous cell carcinomas (SCCs) early in life
  • Multiple BCCs develop early in life in patients with basal cell nevus syndrome or Bazex syndrome
Terminology
  • Trichoblastic carcinoma may be a more accurate term due to its predominant follicular differentiation and possible follicular origin
Epidemiology
  • ~900,000 new individuals are diagnosed with BCC per year in US
  • Occurs in all races, but much more often in fair skinned people
  • Usually in patients >40 years of age
  • More often in men than in women (male : female = 1.6:1)
Sites
  • Mainly sun exposed skin, in any hair bearing area (e.g. head and neck)
  • Also at sites with limited or no sun exposure
Pathophysiology
  • Mutations of PTCH gene identified in most syndromic and sporadic BCCs
Etiology
  • Associated with UV light exposure (particularly intermittent intense exposure), history of radiation treatment
  • Associated with various syndromes: basal cell nevus syndrome; Bazex syndrome; xeroderma pigmentosum
Clinical Features
  • Clinical appearance often parallels the histologic subtype
  • Most common appearance is a papule or nodule with telangiectasias, which may be eroded or ulcerated (ulcus rodens / rodent ulcer)
  • Papules of BCC may clinically resemble a nevus, fibroma or folliculitis
  • Basal cell carcinoma may also manifest as an erythematous patch, papule, nodule or plaque, which is often eroded, ulcerated or indurated
  • Usually only local growth; may be locally destructive with significant morbidity depending on location and size
  • Pigmented BCC may mimic a melanocytic neoplasm
  • Metastases are exceedingly rare (preferred sites: lymph nodes, lung, bones)

Variants:
  • Common subtypes important to distinguish for management purposes:
    • Nodular:
      • Large tumor nodules in the dermis
      • Generally circumscribed
    • Superficial:
      • Tumor nests growing multifocally from the epidermis
      • Minimal to no component detached in the dermis
      • Generally multicentric and grows radially / laterally
      • Arises in skin of trunk and other sites with sparse fine hairs and thin epidermis
      • Has high recurrence rate, tumors may also regress; candidate for topical treatment
    • Infiltrative / Morpheaform:
      • Angulated narrow tumor nests growing in an infiltrative manner at the leading edge of the tumor
      • Higher recurrence rate
      • More likely to find perineural invasion
      • Indication for Moh's microsurgery
    • Basosquamous (metatypical) carcinoma:
      • Basal cell carcinoma plus admixed foci indistinguishable from squamous cell carcinoma (NOT the same as focal squamous differentiation in BCC, which is commonly seen)
      • More aggressive than classic basal cell carcinoma (J Am Acad Dermatol 2009;60:137)
      • May metastasize

Basal cell nevus syndrome:
  • Also called Gorlin's syndrome
  • Due to mutations in PTCH (patched) gene on 9q22.3
  • Autosomal dominant, young patients with multiple basal cell carcinomas (with more varied histologic types than normal, often superficial and multicentric, often with osteoid), palmar pits (in situ basal cell carcinomas), dural calcification, keratinous cysts of jaws, skeletal abnormalities, occasional abnormalities of CNS, mesentery and endocrine organs (medulloblastoma, ovarian fibromas)
Prognostic Factors
  • Histologic subtypes: infiltrative, morpheaform, micronodular, basosquamous
  • Dense fibrous stroma and loss of peripheral palisading
  • Reduced expression of syndecan-1 and BCL2
  • Greater expression of p53 and aneuploidy
  • Perineurial invasion
  • Positive margins
Case Reports
Treatment
  • Surgical: saucerization, standard full thickness excision, Mohs micrographic surgery, curettage with or without electrodesiccation, cryosurgery
  • Medical: topical 5-fluorouracil, imiquimod
  • Radiation
Clinical Images
Images hosted on other servers:

A basal cell carcinoma on the back

Raised border and central ulceration

Waxy BCC

Nodular with telangiectasias


Atrophy and friability

Nodular (left) and pigmented (right)

BCC in 75 year old man


BCC of nose

Red, waxy nodule with visible telangiectasias

BCC "rodent ulcer" in a sun exposed area

Gross Description
  • Reddish tan to pink papules or nodules, with or without central ulceration, often with telangiectasia (prominent subepidermal vessels)
  • Atrophic to indurated, scar-like lesions typically will show an infiltrative histologic pattern
Micro Description
  • Basaloid cells with scant cytoplasm and elongated hyperchromatic nuclei, peripheral palisading, peritumoral clefting and mucinous alteration of surrounding stroma
  • Also mitotic figures, apoptotic bodies
  • The presence of myxoid stroma and peripheral clefting has been suggested to be most helpful to distinguish BCC from other basaloid tumors
  • Many secondary features may occur, such as dystrophic calcification, amyloid deposition or inflammatory reactions with or without partial regression

Other variants of histopathologic interest:
  • Clear cell basal cell carcinoma:
    • Tumor cells with prominent cytoplasmic vacuoles or signet ring morphology
  • Fibroepithelial tumor:
    • Also called Pinkus' tumor, fibroepithelioma
    • Polypoid variant, often on back, with abundant stroma
  • Granular basal cell carcinoma:
    • Contains tumor cells resembling granular cell tumor
    • No clinical significance
  • Infundibulocystic basal cell carcinoma:
    • Hair follicle differentiation
Micro Images
Images hosted on PathOut server:

Superficial tumor
contributed by
Dr. Amy Lynn,
Toledo, Ohio


Images hosted on other servers:

Nodular

Area of ulceration

BCC below epidermis

Superficial, various images


Cystic basal cell carcinoma

Infiltrative BCC

Micronodular basal cell carcinoma


Superficial basal cell carcinoma

Micrograph of a basal cell carcinoma,
showing characteristic histomorphologic
features (peripheral palisading, myxoid
stroma, artefactual clefting); H&E stain



Flickr images:

Forehead lesion

Infiltrative BCC, courtesy of Sara Shalin, M.D., Ph.D.

Positive Stains
Negative Stains
Molecular / Cytogenetics Description
  • +18, +9, +20, +7, +5
  • Also loss of heterozygosity at 9q22.3 and trisomy 6
Differential Diagnosis