• Clinical science

Basal cell carcinoma (Basalioma)

Summary

Basal cell carcinoma (BCC) is a malignant neoplasm and the most common type of skin cancer. BCC primarily affects individuals with light skin. Although excessive sun exposure is the primary risk factor, chemicals (e.g., arsenic) and genetic factors also increase the risk of developing BCC. Slow-growing nodules (classic "pearly" appearance) that tend to ulcerate during the course of disease are the characteristic lesions associated with BCC. Surgical excision is the treatment of choice. Because BCC does not metastasize, the prognosis is usually excellent.

Epidemiology

  • Most common malignant skin tumor
  • Incidence: 2–3 million people per year in the US
  • Sex: > (∼ 2:1)

References:[1][2]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

References:[5][1]

Clinical features

  • Localization [6][7]
    • Typically in areas of skin exposed to sun
    • Basal cell carcinoma of the face typically occurs above the line joining the earlobe and the corner of the mouth
    • The palms, soles of the feet, and mucous membranes are rarely affected.
  • Clinical appearance
  • Growth
    • Slow-growing, over months to years
    • Typically painless
    • Locally invasive
    • Very rarely metastasizes

Most basal cell carcinomas occur on areas of sun-exposed skin.

To remember the usual site of occurrence of basal cell carcinoma, think of: “Basal cell carcinoma is more common aBove the upper lip.”

References:[1][8]

Subtypes and variants

There are several types of basal cell carcinoma:

References:[9][5][10]

Diagnostics

Basal cell carcinoma lesions are usually readily identifiable, but the diagnosis should always be histologically confirmed (via full-thickness biopsy done at the edge of the lesion).

  • Dermoscopy: initial clinical evaluation of suspected BCC lesions (dermoscopy cannot confirm BCC)
  • Excisional biopsy: (full-thickness biopsy or partial-thickness biopsy) first choice
    • Most accurate assessment of the histologic subtype of the tumor
  • Wedge biopsies: used to evaluate large lesions

References:[11][5]

Pathology

References:[5]

Differential diagnoses

Trichoepithelioma

  • Definition: rare, benign tumor of the hair follicle that usually occurs in younger individuals
  • Lesions:
    • Skin-colored, firm papules
    • May occur as single or multiple lesions
  • Localization: mainly nose and cheeks
  • Treatment: excision or laser ablation

Other differential diagnoses

References:[5]

The differential diagnoses listed here are not exhaustive.

Treatment

References:[5]

Prognosis

  • Excellent prognosis with surgical excision because of the low rate of metastasis
  • 1. Wu PA. Epidemiology, pathogenesis, and clinical features of basal cell carcinoma. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. http://www.uptodate.com/contents/epidemiology-pathogenesis-and-clinical-features-of-basal-cell-carcinoma. Last updated February 17, 2017. Accessed March 14, 2017.
  • 2. Skin Cancer Foundation. Skin Cancer Facts and Statistics. http://www.skincancer.org/skin-cancer-information/skin-cancer-facts. Accessed March 14, 2017.
  • 3. Marçon CR, Maia M. Albinism: epidemiology, genetics, cutaneous characterization, psychosocial factors. An Bras Dermatol. 2019; 94(5): pp. 503–520. doi: 10.1016/j.abd.2019.09.023.
  • 4. Daya-Grosjean L. Xeroderma Pigmentosum and Skin Cancer. Springer New York; 2020: pp. 19–27.
  • 5. Marks JG Jr, Miller JJ . Lookingbill and Marks' Principles of Dermatology. Saunders Elsevier; 2013.
  • 6. Choi JH, Kim YJ, Kim H, Nam SH, Choi YW. Distribution of Basal Cell Carcinoma and Squamous Cell Carcinoma by Facial Esthetic Unit. Archives of Plastic Surgery. 2013; 40(4): p. 387. doi: 10.5999/aps.2013.40.4.387.
  • 7. Janjua OS, Qureshi SM. Basal Cell Carcinoma of the Head and Neck Region: An Analysis of 171 Cases. Journal of Skin Cancer. 2012; 2012: pp. 1–4. doi: 10.1155/2012/943472.
  • 8. Şahan B, Çiftçi F, Özkan F, Öztürk V. The importance of frozen section-controlled excision in recurrent basal cell carcinoma of the eyelids. Turk J Ophthalmol. 2016; 46(6): pp. 277–281. doi: 10.4274/tjo.48640.
  • 9. James WD, Berger T, Elston D. Andrews' Diseases of the Skin: Clinical Dermatology. Philadelphia, PA: Elsevier Health Sciences; 2015.
  • 10. Oakley A. Basal cell carcinoma. http://www.dermnetnz.org/topics/basal-cell-carcinoma/. Updated December 1, 2015. Accessed March 14, 2017.
  • 11. Pestana C. Dr. Pestana's Surgery Notes: Top 180 Vignettes for the Surgical Wards. Kaplan; 2015.
  • Bader RS. Basal Cell Carcinoma. In: Basal Cell Carcinoma. New York, NY: WebMD. http://emedicine.medscape.com/article/276624-overview. Updated September 21, 2016. Accessed February 17, 2017.
last updated 09/21/2020
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