Primary cutaneous sarcomatoid squamous cell carcinoma: a comprehensive clinicopathological and immunohistochemical study focusing on diagnostic pitfalls

PCSSCC can be a difficult neoplasm to diagnose, as it can appear histologically similar to other malignant spindle cell neoplasms. We describe 74 cases of PCSSCC, highlighting their salient clinical, histopathological and immunohistochemical features, and discuss the potential diagnostic pitfalls in distinguishing this entity from other malignant neoplasms. Our results indicate that a combination of thorough histological inspection coupled with an adequate battery of immunohistochemical stains is necessary to support the diagnosis of PCSSCC.