Hormone -Refractory Prostatic Adenocarcinoma Mimicking Basal Cell Carcinoma: A Case Report

Prostate cancer is an androgen-driven malignancy. Patients with late-stage prostate cancer often receive androgen-deprivation therapy to suppress the disease progression. Under the selection pressure, some prostate cancers transform to androgen-independent cancers. Treatment-induced small cell neuroendocrine carcinoma is one of the examples. In the last decade, patients with disseminated prostate cancer frequently received second-generation androgen-deprivation agents, such as abiraterone, enzalutamide, and apalutamide. Those more potent drugs have led to an emergence of a novel type of androgen-independent carcinoma named "double-negative" prostate cancer, which is immunohistochemically negative for both neuro-endocrine markers and androgen targets. In this report, we present a typical case of "double-negative" end-stage prostate cancer that morphologically resembled basal cell carcinoma of prostate, basaloid large nest type.