Host immune responses and peritumoral stromal reactions in different basal cell carcinoma subtypes: histopathological comparison of basosquamous carcinoma and high-risk and low-risk basal cell carcinoma subtypes

Abstract

Background/aim: The literature does not include sufficient data on the associations between host immune responses and stromal reactions in different basal cell carcinoma (BCC) subtypes. The aim of the study was to compare host immune responses and stromal reactions between basosquamous carcinoma (BSC) and high-risk (HR) and low-risk (LR) BCC subtypes. Materials and methods: The study included 35 BSC, 40 HR-BCC, and 40 LR-BCC patients. Age, sex, lesion location, density of peritumoral/adjacent perivascular inflammation, presence of lymphoid follicle formation, and stromal reaction type were compared between groups. Results: In all 3 groups, age, sex distribution, and lesion location were similar. Overall, 70% of lesions in the LR-BCC group exhibited mild peritumoral inflammation, whereas in the BSC and HR-BCC groups dense inflammation was observed in 50% and 57.5% of lesions, respectively (P < 0.001). All lesions (100%) in the LR-BCC group had fibromyxoid stroma, whereas 61.8% and 80% of lesions in the BSC and HR-BCC groups, respectively, had desmoplastic stroma (P < 0.001). Conclusion: The BSC and HR-BCC groups were similar in terms of host immune responses and stromal reactions. Furthermore, BSC and HR-BCC were associated with dense peritumoral inflammation, adjacent perivascular inflammation, and desmoplastic stroma.