Recurrent basal cell carcinoma: a clinicopathological study and evaluation of histomorphological findings in primary and recurrent lesions.

BACKGROUND: Basal cell carcinoma (BCC) of the skin is now the most common malignancy in the human population. One of the most negative features of this disease is frequent tumor recurrence. Unfortunately, all of the traditional diagnostic criteria have failed to definitively predict which patients should be considered at high risk of recurrence.
OBJECTIVE: The aim of this study was to evaluate the prevalence, topographical localization, and histomorphological features of recurrent BCCs.
METHODS: Biopsy samples and clinical data from 30 consecutive patients (15 women and 15 men) with 31 recurrent BCCs diagnosed from January 2007 to September 2010 were analyzed retrospectively. The mean age of the individuals at the time of diagnosis of recurrence was 68.2 years (range 32 to 97 years). Histological types and other pathological findings of original and relapsing BCCs, as well as the time between them, were able to be compared in 24 cases.
RESULTS: Recurrent carcinomas represented 4.9% of all diagnosed cases during the observed period. Recurrence time varied from 4 to 105 months with a mean time of 31.2 months. The majority of recurrences occurred within 3 years after the primary treatment. The topographic localization of tumors was as follows: auricles (n = 5), cheeks (n = 4), medial canthus (n = 4), periauricular regions (n = 3), temporal areas (n = 3), paranasal regions (n = 3), nose (n = 3), forehead (n = 1), lower eyelid (n = 1), mandible (n = 1), chin (n = 1), neck (n = 1), and back (n = 1). Histologically, 50% of primary and 54.8% of recurrent BCCs demonstrated at least partial aggressive-growth features. Comparing primary and corresponding relapsing BCCs, 50% of them showed an identical type, in 16.7% the recurrent tumor had developed a more aggressive histological picture, and in 20.8% the histomorphology had became more benign. Of all primary tumors previously removed by total extirpation, 54.5% were resected completely and 45.5% incompletely.
CONCLUSIONS: BCC recurrences may vary considerably with respect to various tumor- and host- -related factors, and so it is impossible to predict them precisely. Although aggressive histological types and positive excision margins are considered the strongest predictors, we demonstrated that half of the primary cancers had shown an indolent character, and that more than half of them had appeared to be completely resected. We can conclude that all patients that have had BCCs removed should be re-examined regularly even after microscopically adequate excisions, or lesions with an indolent histomorphology. Careful monitoring must be undertaken for at least 3 years; however, the most appropriate course is a lifetime of regular follow-up.