Basosquamous cell carcinoma: a survey of 76 patients and a comparative analysis of basal cell carcinomas and squamous cell carcinomas

Background: Basosquamous carcinoma (BSC) is a rare epithelial tumor with a still confusing terminology. Since 2005 a more comprehensive and broader classification has existed. Aim: To retrospectively review our cases of BSC according to the new WHO definition and to re-evaluate their clinical and demographic characteristics and the margin involvement after traditional surgical excision. The data were compared with the same results obtained by basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs). Patients and Methods: Histologically confirmed carcinomas observed in our Department during a sixteen-year period (1994-2011) were studied. Surgical excision was evaluated following the international guidelines. Histopathologic subtypes of BSC were classified in accordance with accepted criteria. Results: Seventy-six patients had a BSC, 305 a SCC, 3,643 a BCC. There were significant differences among the median age of BSCs, the total BCCs and Non-Aggressive BCCs (74.7, 68.8 and 68.3 years respectively; p<0.05). BSC was more significantly located on head-neck region than Non-Aggressive BCC (p<0.04), and less on trunk than Mixed Histology BCC (p<0.01) and Non-Aggressive BCC (p<0.005). BSC has higher prevalence of positive margins after excision than total (p<0.03) and Non-Aggressive BCC (p<0.001). Conclusion: Basosquamous carcinoma fits to a tumor type with a different behavior pattern from non-aggressive basal cell carcinoma and more similar to squamous cell carcinoma or aggressive variants of basal cell carcinoma. Its infiltrative growth and the stromal reaction patterns give enough evidence to support the notion of considering basosquamous carcinoma as a relatively aggressive tumor.