Incisional biopsy critical in obtaining definitive diagnosis in a clinically challenging case.

Tissue-sparing biopsy techniques are frequently used in clinical practice but can result in misdiagnosis of large, clinically challenging lesions. We present a case of a 70-year-old man with hidradenocarcinoma of the left chin, a diagnosis that was delayed owing to repeated superficial biopsies that were negative for disease. Diagnosis was ultimately obtained via an incisional biopsy. We discuss the clinical features of hidradenocarcinoma and why this diagnosis can be easily missed with superficial biopsies. It is important that dermatologists consider incisional biopsies in the workup of clinically challenging lesions for which malignancy is considered.