Basal cell carcinoma (BCC) is the most common skin cancer derived from basaloid epithelia located in the follicular bulges, in the anagen hair bulbs and the follicular matrix cells, and in specific basaloid cells of the interfollicular epidermis. Recently, the occurrence of BCC has increased. This is because the elderly population has increased due to the extension of the average life span, improved standard of living and changes in environment and lifestyle have increased exposure to sunlight, industrialization has contributed to the destruction of the ozone layer, exposure to harmful substances has increased, and improved awareness of patients have lead to more frequent visits to the hospital.
BCC most commonly occurs in sun-exposed sites such as the face and neck, where 80-90% of BCCs occur. Ten to fifteen percent of BCCs occur in non-sun-exposed sites and usually occur in the axilla, buttock, groin, penis, scrotum, vulva, breast and nipple. Among these, the occurrence of BCC in the axilla is extremely rare, and to date, only 5 cases have been reported in Korean patients (Table 1). BCC can be classified histologically into nodulocystic (35.4%), mixed (30.1%), infiltrative (9.3%), superficial (6.7%), micronodular (6.2%), adenoid (5.9%), metatypical (4.0%), morpheaform (2.1%), and fibroepithelioma types (0.3%)2. The occurrence of adenoid BCC is rare, and relatively low compared to the nodulocystic BCC, which is the most common type of BCC2. Among the 5 cases of BCC in the axilla reported in Korean patients, there were no other such cases of adenoid BCC.
Ultraviolet radiation is considered the single most important risk factor for BCC, and arsenic, coal tar derivatives, irradiation, scars, burn sites, chronic inflammation, ulcer and immune deficiency are also associated with the occurrence of BCC. The genodermatoses that enhance the risk of BCC include xeroderma pigmentosa, Rasmussen syndrome, Rombo syndrome, Bazex-Christol-Dupre syndrome, albinism and Darier’s disease. These syndromes variably either decrease epidermal pigmentation and thus increase the risk of UV light-induced onco- genic transformation or promote genotypic instability in the dermis. In this case, none of these risk factors or genodermatoses were found. levitra professional
Although ultraviolet radiation is thought to be the primary risk factor in development of BCC, the precise relationship is not as clear as with squamous cell carcinoma (SCC). For example SCC occurs most commonly in highly sun-exposed areas on the dorsal hands and forearms, forehead, superficial pinna, and lower lip. SCC also correlates with chronic, cumulative ultraviolet radiation exposure. In contrast, BCC is less likely to arise on the dorsal hands and it occurs more commonly in sun- protected areas than SCC.