Basal cell carcinoma (BCC), the most common skin cancer, is mostly localized in the cephalic region. The BCC that arise in sun-protected sites are quite uncommon. If ultraviolet rays are on the base of the genesis of classical BCC, they are insufficient to explain the occurrence of CBC in non-sun-exposed parts of the body. The aim of our work is to highlight the epidemiological, clinical and evolutive characteristics of extra cephalic BCC.
Materiel et methods
Retrospective study of the files of patients followed for BCC that arise in sun-protected sites including those of the neck, and having a histological confirmation, over a period of 20 years (1995-2014).
68 patients with one or more extra cephalic BCC (76 BCC) were seen over 25 years, they presented 5,5% of 1 237 patients with BCC, recorded during the same period. We noted a previous trauma in the same seat (2 cases), a loco regional radiotherapy for blood disease (2cases) or for ringworm (1case), an oculocutaneous albinism (2cases) and a xeroderma pigmentosum (1case). The average age of onset of the BCC was 57,5 years (range : 11 and 102 ans). Mean age at diagnosis was 62 years. Median duration of BCC pre-diagnosis was 4,7 years. All our patients were Caucasian with a male to female sex ratio of 1,6. The size of the tumor, ranging from 0.5 to 15 cm (mean size : 2,6 cm) was over than 10 cm in 2 cases. The trunk was the most affected site (47.5%) with predominance (30%) at its front side (abdomen, thorax). The nodular form was predominant (35 cases : 46%) followed by the flat scar form (10 cases : 13%). Five patients (7.5%) had multiple simultaneous BCC in sun-protected sites. The histological type was mostly nodular (43 cases : 56.5%) followed by the ulcerated type (19 cases : 25%). Invasive tumor was noted in 5 cases (2 ulcerative and 3 nodular types). No lymphadenopathy or metastasis was noted. Wide local excision was the treatment method used most commonly (75 cases). Only 1 case was treated with CO2 laser. Adjuvant radiotherapy was needed in one case. À follow-up from 5 months to 5 years did not notice recurrence or metastasis.
The BCC occurring on sun-protected regions is a rare phenomenon. The concept of contributing factors is a reality. The predominance of the arising in the trunk and the nodular form is clear. The prognosis joins that of other BCCsLe texte complet de cet article est disponible en PDF.
Keywords : basal cell carcinoma-histology-anatomy