4.1 Clinical features of basal cell carcinoma
Background[edit source]
There are three common growth patterns of basal cell carcinoma (BCC) that have a distinctive clinical presentation:[1]
- superficial multifocal
- nodular
- sclerosing (morphoeic).
Numerous histological subtypes of BCC have been described, but most are uncommon and do not have distinctive clinical presentations. Some may be multiple and difficult to diagnose.
Superimposed on any of these growth patterns may be ulceration or pigmentation. Although ulceration and pigmentation lead to a distinctive clinical appearance, these features do not correspond to a specific histological growth pattern and are therefore no longer considered to represent separate subtypes of BCC.
Immunosuppression for organ transplantation predisposes to BCC (see: Organ transplantation and other conditions associated with prolonged immunosuppression).[2][3] Left untreated, over years, BCCs can cause significant morbidity for the patient.
Overview of evidence (non-systematic literature review)[edit source]
Dermoscopy[edit source]
Dermoscopy (surface microscopy, epiluminescence microscopy, dermatoscopy) is a technique that is established as a significant aid in the diagnosis of pigmented lesions, particularly melanoma. More recently, it has been shown to have benefit in the diagnosis of BCC and other non-pigmented lesions, such as cutaneous squamous cell carcinoma (cSCC) in situ (also known as Bowen’s disease or intra-epidermal squamous cell carcinoma). Dermoscopy is also useful in distinguishing between melanoma and pigmented BCC.[4]
The dermatoscope is a handheld magnifying device which requires formal training and continuous practice with the technology if the operator is to become proficient with its use in diagnosis.[5][6]
Dermoscopy is useful in enhancing diagnosis of basal cell carcinoma. For effective implementation of dermoscopy it is imperative that operators receive appropriate training and maintain their skills.[4][5][6][7][8][9][10][11]
Accuracy of clinical diagnosis of basal cell carcinoma[edit source]
The diagnostic accuracy of clinical examination by experienced dermatologists for the diagnosis of BCC among randomly selected samples from the general community is around 59%[12] to 65%.[13] This is somewhat lower than would be expected in clinical practice because of the much lower prevalence of skin cancers in the community, compared with the clinical setting.
No data are available regarding the diagnostic accuracy of clinicians in Australia, but in a clinical practice setting in the USA a diagnostic accuracy of 70% has been reported for university-based dermatologists. These observations indicate that, in spite of the frequency of BCC and in spite of high levels of clinical experience, diagnosis may be difficult on occasion.
Superficial basal cell carcinoma[edit source]
Superficial BCC is a subtype of BCC that commonly occurs in Australians. Superficial BCCs generally occur on the trunk or limbs. In younger people they occur more often than other growth patterns.
Clinical features[edit source]
Superficial BCC usually presents as a reasonably well-defined, erythematous, scaling or slightly shiny macular lesion.[14][1] The degree of erythema present may vary and will be increased by stretching or rubbing the lesion. Stretching the lesion will highlight the shiny surface and may reveal, to the naked eye, a peripheral thread-like pearly rim or islands of pearliness distributed through the lesion.
A minority of superficial BCCs are symptomatic, with itching being the most common symptom. Although these lesions are readily eroded by minor trauma, a history of ulceration or bleeding is uncommon.
Causation[edit source]
Exposure to sunlight is the most common cause of superficial BCC. Multiple superficial BCCs may also occur in the context of arsenic intoxication. Other stigmata of arsenic intoxication include punctate palmoplantar keratoderma, scattered macular hypopigmentation and longitudinal pigmented bands or horizontal hyperpigmented stripes in fingernails and toenails.
Clinical course[edit source]
Many superficial BCCs will progressively enlarge over months to years and if left, may reach 5–10cm in diameter. Some may be relatively stable and a few will regress. With time, areas of nodular and even sclerosing growth pattern may supervene within the original superficial BCC.
Differential diagnosis[edit source]
Superficial BCC should be distinguished from:
- actinic (solar) keratosis
- Bowenoid keratosis
- Bowen's disease
- amelanotic melanoma.
As the management of superficial BCC may differ from that of these other tumours, a biopsy to obtain definitive pathology should be undertaken prior to definitive treatment. The appearance may suggest an inflammatory dermatosis such as eczema or psoriasis. However, the clinical history of superficial BCC is one of inexorable enlargement over months or years while inflammatory lesions are generally more transient. Dermoscopy may be a helpful tool in diagnosis of these lesions.[15]
Nodular basal cell carcinoma[edit source]
Nodular BCCs are more often found on the head and neck in people who are somewhat older on average than those with superficial BCC.[1][16]
Clinical features[edit source]
Nodular BCC typically presents as a shiny, translucent (pearly), telangiectatic papule or nodule. The translucent or pearly appearance is more obvious if the clinician stretches the skin during examination. As the lesion enlarges the dilated capillaries may be seen coursing across the surface of the lesion. These are often radially arranged.
Ulceration may occur with time and may lead to central umbilication of the lesion with a more raised rolled border. Islands of pigmentation may become clinically visible and the lesion may become darkly pigmented, suggesting melanoma. Like superficial BCC, these may be associated with sensory symptoms (only in a minority of cases) but, unlike superficial BCC, nodular lesions often ulcerate and bleed.
Differential diagnosis[edit source]
Nodular BCCs need to be differentiated from squamous cell carcinoma, amelanotic nodular melanoma and, rarely, Merkel cell carcinoma.
The differential diagnosis also includes various benign lesions.
Clinical course[edit source]
Nodular BCCs may progressively enlarge, invade locally and ulcerate over a period of months to years.
Sclerosing basal cell carcinoma[edit source]
Sclerosing (morphoeic) BCC has a similar body-site distribution to that of nodular BCC. Sclerosing BCCs are usually of long standing and tend to be deeply invasive.
Clinical features[edit source]
These lesions have a sclerosing growth pattern with fibrosis surrounding areas of BCC. Basal cell carcinomas that are predominantly sclerosing have the appearance of a pale scar.
Palpation usually reveals firm induration, which may extend more widely and deeply than is evident on inspection. Sclerosing changes will frequently supervene in longstanding nodular BCCs and these lesions may retain some clinical features of nodular BCC.
Sclerosing BCCs are frequently asymptomatic. Those with nodular elements may show all the same symptoms as nodular BCCs.
Clinical course[edit source]
Sclerosing BCCs may remain undetected by doctor and patient for many years and may slowly enlarge and deepen to reach a large size before being treated.
The major differential diagnosis of sclerosing BCC is scar tissue. Biopsy is necessary to establish the diagnosis.
Recurrence in sclerosing BCCs can be common, and therefore requires regular monitoring. Some recurrence may be due to local incomplete excision, with satellite islands of BCC either having not been visible at the time of surgery, or being distant from the primary lesion, particularly in those with certain genetic syndromes such as Gorlin’s syndrome (naevoid BCC syndrome) or those with immunosuppression.
Sclerosing lesions should be reviewed more frequently and may benefit from specialist review.
Influence of subtype on prognosis of basal cell carcinoma[edit source]
Certain BCC subtypes (Table 1) are associated with a poor prognosis.
Table 1. Tumour-specific factors associated with recurrence of basal cell carcinoma
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References[edit source]
- ↑ 1.0 1.1 1.2 McCormack CJ, Kelly JW, Dorevitch AP. Differences in age and body site distribution of the histological subtypes of basal cell carcinoma. A possible indicator of differing causes. Arch Dermatol 1997 May;133(5):593-6 Available from: http://www.ncbi.nlm.nih.gov/pubmed/9158412.
- ↑ Ong CS, Keogh AM, Kossard S, Macdonald PS, Spratt PM. Skin cancer in Australian heart transplant recipients. J Am Acad Dermatol 1999 Jan;40(1):27-34 Available from: http://www.ncbi.nlm.nih.gov/pubmed/9922009.
- ↑ Kricker A, Armstrong BK, English DR, Heenan PJ. Pigmentary and cutaneous risk factors for non-melanocytic skin cancer--a case-control study. Int J Cancer 1991 Jul 9;48(5):650-62 Available from: http://www.ncbi.nlm.nih.gov/pubmed/2071226.
- ↑ 4.0 4.1 Demirtaşoglu M, Ilknur T, Lebe B, Kuşku E, Akarsu S, Ozkan S. Evaluation of dermoscopic and histopathologic features and their correlations in pigmented basal cell carcinomas. J Eur Acad Dermatol Venereol 2006 Sep;20(8):916-20 Available from: http://www.ncbi.nlm.nih.gov/pubmed/16922937.
- ↑ 5.0 5.1 Argenziano G, Puig S, Zalaudek I, Sera F, Corona R, Alsina M, et al. Dermoscopy improves accuracy of primary care physicians to triage lesions suggestive of skin cancer. J Clin Oncol 2006 Apr 20;24(12):1877-82 Available from: http://www.ncbi.nlm.nih.gov/pubmed/16622262.
- ↑ 6.0 6.1 Cancer Council Australia Melanoma Guidelines Working Party. Clinical practice guidelines for the diagnosis and management of melanoma. [homepage on the internet] Sydney, New South Wales: Cancer Council Australia; 2018 [cited 2018 Oct 11]. Available from: https://wiki.cancer.org.au/australia/Guidelines:Melanoma.
- ↑ Menzies SW, Westerhoff K, Rabinovitz H, Kopf AW, McCarthy WH, Katz B. Surface microscopy of pigmented basal cell carcinoma. Arch Dermatol 2000 Aug;136(8):1012-6 Available from: http://www.ncbi.nlm.nih.gov/pubmed/10926737.
- ↑ Trigoni A, Lazaridou E, Apalla Z, Vakirlis E, Chrysomallis F, Varytimiadis D, et al. Dermoscopic features in the diagnosis of different types of basal cell carcinoma: a prospective analysis. Hippokratia 2012 Jan;16(1):29-34 Available from: http://www.ncbi.nlm.nih.gov/pubmed/23930054.
- ↑ Caresana G, Giardini R. Dermoscopy-guided surgery in basal cell carcinoma. J Eur Acad Dermatol Venereol 2010 Dec;24(12):1395-9 Available from: http://www.ncbi.nlm.nih.gov/pubmed/20384678.
- ↑ Lallas A, Argenziano G, Zendri E, Moscarella E, Longo C, Grenzi L, et al. Update on non-melanoma skin cancer and the value of dermoscopy in its diagnosis and treatment monitoring. Expert Rev Anticancer Ther 2013 May;13(5):541-58 Available from: http://www.ncbi.nlm.nih.gov/pubmed/23617346.
- ↑ Zalaudek I, Argenziano G, Giacomel J. Dermatoscopy of Non-Pigmented Skin Tumors: Pink - Think - Blink. Boca Raton, FL, USA: CRC Press; 2015.
- ↑ Kricker A, English DR, Randell PL, Heenan PJ, Clay CD, Delaney TA, et al. Skin cancer in Geraldton, Western Australia: a survey of incidence and prevalence. Med J Aust 1990 Apr 16;152(8):399-407 Available from: http://www.ncbi.nlm.nih.gov/pubmed/2329947.
- ↑ Presser SE, Taylor JR. Clinical diagnostic accuracy of basal cell carcinoma. J Am Acad Dermatol 1987 May;16(5 Pt 1):988-90 Available from: http://www.ncbi.nlm.nih.gov/pubmed/3584583.
- ↑ Mackie R. An illustrated guide to the aetiology, clinical features, pathology and management of benign and malignant cutaneous tumours. London: Martin Dunitz Ltd; 1989.
- ↑ Pan Y, Chamberlain AJ, Bailey M, Chong AH, Haskett M, Kelly JW. Dermatoscopy aids in the diagnosis of the solitary red scaly patch or plaque-features distinguishing superficial basal cell carcinoma, intraepidermal carcinoma, and psoriasis. J Am Acad Dermatol 2008 Aug;59(2):268-74 Available from: http://www.ncbi.nlm.nih.gov/pubmed/18550207.
- ↑ Bastiaens MT, Hoefnagel JJ, Bruijn JA, Westendorp RG, Vermeer BJ, Bouwes Bavinck JN. Differences in age, site distribution, and sex between nodular and superficial basal cell carcinoma indicate different types of tumors. J Invest Dermatol 1998 Jun;110(6):880-4 Available from: http://www.ncbi.nlm.nih.gov/pubmed/9620293.