Anatomic location and histopathologic subtype of basal cell carcinomas in adults younger than 40 or 90 and older: any difference?

Differences in age, site, and histopathologic subtype exist in basal cell carcinoma (BCC). OBJECTIVE: To compare the distribution of BCCs in patients younger than 40 with that of those aged 90 and older according to sex, site, and subtype. METHODS & MATERIALS: One hundred seventy-five BCCs were examined. The site was classified as head and neck, trunk, or limbs and the subtype as nodular, superficial, or morpheic-infiltrative. RESULTS: Younger exhibited a lower prevalence of BCCs on the head and neck (36.0% vs 57.3%, p<.01) and a higher prevalence on the trunk (59.3% vs 31.5%, p<.01) and of superficial BCCs (43.0% vs 31.5%, p<.05) than older patients. Site was associated with subtype in younger (p<.001) and older (p=.004) patients. Superficial BCCs were mostly on the trunk (p<.001), with a higher prevalence in younger patients (86.5% vs 62.5%, p<.05). Morpheic BCCs were mostly on the head and neck (p<.001), and prevalence did not differ between age groups. Nodular BCCs were mostly on the head and neck in older patients (p=.011). Subtype was independently associated with site (p=.005) but not with age or sex. CONCLUSION: A different distribution of site and subtype occurs in younger and older patients. Subtype is associated with site independent of age and sex. These findings suggest that, at least in some patients, the anatomic location of BCC may favor the development of a particular subtype