Basal cell carcinoma

Basal cell carcinoma: biology, morphology and clinical implications

“…The prevalence is roughly 1 in 56 000. 8 In most cases, the abnormality represents a mutation in the human homologue of the Drosophila patched gene (PTCH). 25 Perturbation of this tumor suppressor gene on chromosome 9 q22-q31 26,27 results in upregulated cell proliferation.…”

“…7 Typically, BCCs occur in the fourth decade of life and beyond 8 although exceptions to this occur, in particular in the setting of specific genodermatoses or in patients with immune compromise. 9 As sun exposure plays a role in the development and transformation of BCC, 7 patients with light skin phenotypes are particularly predisposed as expected; this includes in the context of blue eyes, red hair and easy freckling 8 as well as those whose occupational or leisure activities lead them to pronounced and prolonged sun exposure. Additional risk factors for BCC include the exposure to arsenic, coal tar derivatives and irradiation, although by far ultraviolet (UV) light is the most important factor in lesion development and progression.…”

“…Additional risk factors for BCC include the exposure to arsenic, coal tar derivatives and irradiation, although by far ultraviolet (UV) light is the most important factor in lesion development and progression. 5,7,8,10,11 BCC may, like squamous cell carcinoma, arise in the setting of scars, draining sinuses, ulcers, burn sites and foci of chronic inflammation. 8,10, 11 The role of immune compromise in provoking an increased risk of BCC may be due to impairment of the immune surveillance of oncogenic viruses.…”

“…5,7,8,10,11 BCC may, like squamous cell carcinoma, arise in the setting of scars, draining sinuses, ulcers, burn sites and foci of chronic inflammation. 8,10, 11 The role of immune compromise in provoking an increased risk of BCC may be due to impairment of the immune surveillance of oncogenic viruses. 12 The genodermatoses that enhance the risk of BCC include the prototype xeroderma pigmentosa, Rasmussen syndrome, Rombo syndrome, Bazex-Christol-Dupre syndrome, albinism and Darier's disease.…”

“…Other lesions associated with coexistent BCCs include acantholytic processes of diverse type (personal observation), warts, porokeratosis, neurofibromata, nevi sebaceus and epidermal nevi, condylomata accuminata, hemangiomas, cysts of hair follicle derivation, pilomatricomas and a variety of common skin neoplasms such as seborrheic keratoses and melanocytic nevi, which are so common as to make their coexistence with BCC in any given patient a random event in all probability. 8,11,13,14 Basal cell carcinomata have also been reported in collision with a common dermal fibrosing reaction to trauma (ie dermatofibroma), but in this setting the presence of dermal proplastic cytokines could explain the epidermal proliferation. As in nevi sebaceus, the basaloid epidermal proliferation overlying a dermatofibroma often shows a form of follicular stromal induction suggesting a recapitulation of hair follicle growth.…”