DIFFERENCES IN AGE AND BODY SITE DISTRIBUTION OF THE HISTOLOGICAL SUBTYPES OF BASAL-CELL CARCINOMA - A POSSIBLE INDICATOR OF DIFFERING CAUSES

Objective: To assess if there are any significant differences in the s ex, anatomical site, and age distribution of patients with different h istological subtypes of basal cell carcinoma (BCC). Design: Histopatho logy reports were analyzed with respect to the subtype of BCC, site of a tumor, and age and sex of a patient. Setting: Histopathology report s were reviewed from 1 private laboratory that derived its cases from general practitioners, surgeons, and dermatologists. Patients: Patient s with BCC (N=3885) for whom case data were received by the pathology laboratory from January 2, 1991, to June 12, 1991, were included in th e study. Interventions: None. Main Outcome Measures: Superficial BCCs differed from other subtypes of BCC by occurring more commonly on the trunk and in younger patients. Results: The mean age (56.8 years) of t he patients with superficial BCCs was significantly lower than that of the patients with other subtypes of BCC who were examined (P<.001); t he mean ages of the patients with these other subtypes were as follows : nodulosuperficial BCC, 62.9 years; nodular BCC, 63.9 years; nodulomo rpheic BCC, 66.1 years; and morpheic BCC, 66.0 years: The majority of superficial BCCs occurred on the trunk and limbs (73.3%), while the ma jority of all other subtypes occurred on the head and neck. Conclusion s: Superficial BCC differs from the other subtypes of BCC in terms of patient age and tumor site, and these findings may reflect differences in the etiology.