Diagnostic pitfalls: how availability and anchoring biases lead to errors in dermatology

This case highlights the susceptibility of dermatology to misdiagnosis. Availability bias in the clinical setting led to an inadequate biopsy method. Further anchoring bias then potentially influenced histologic interpretation and management decisions. Insufficient appreciation of Kaposi Sarcoma development in the setting of well-controlled HIV also further influenced the diagnosis rendered. Mohs Surgery evaluation allowed for de-biased clinical and histologic assessment, correcting diagnosis. Several overlying factors, such as time pressures, knowledge gaps, and technique limitations, create a reliance on cognitive heuristics. Recognizing these external pressures can help clinicians enhance diagnostic accuracy by systematically considering alternative diagnoses.