An insurer's perspective on error and loss in pathology.

OBJECTIVES: To identify errors in surgical pathology practice that lead to malpractice claims, and to define the frequency and severity of pathology malpractice claims and discuss the implications.
DESIGN: Three hundred seventy-eight pathology malpractice claims reported to The Doctors Company of Napa, Calif, between 1998 and 2003, were reviewed. Nuisance claims and autopsy claims were excluded; the 335 remaining claims were analyzed.
RESULTS: Pathology claim frequency is low. Pathology claim severity is high, especially for claims involving a misdiagnosis of melanoma or a false-negative Papanicolaou test. Fifty-seven percent of claims involved the following 5 categories: breast specimens, melanoma, Papanicolaou smears, gynecologic specimens, and operational error. Sixty-three percent of claims involved failure to diagnose cancer, resulting in delay in diagnosis or inappropriate treatment.
CONCLUSION: A false-negative diagnosis of melanoma is the single most common reason for filing a malpractice claim against a pathologist. Nearly one third of misdiagnoses involve melanoma misdiagnosed as Spitz nevus, "dysplastic" nevus, spindle cell squamous carcinoma, atypical fibroxanthoma, and dermatofibroma.