Medicolegal aspects of error in pathology.

OBJECTIVE

To discuss the various ways error is defined in surgical pathology. To identify errors in pathology practice identified by an analysis of pathology malpractice claims.

DESIGN

Three hundred seventy-eight pathology malpractice claims were reviewed. Nuisance claims and autopsy claims were excluded; 335 pathology claims remained and were analyzed to identify repetitive patterns of specimen type and diagnostic category.

SETTING

All pathology malpractice claims reported to The Doctors Company of Napa, Calif, between 1998 and 2003.

RESULTS

Fifty-seven percent of malpractice claims involved just 5 categories of specimen type and/or diagnostic error, namely, breast specimens, melanoma, cervical Papanicolaou tests, gynecologic specimens, and system (operational) errors. 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 was the single most common reason for filing a malpractice claim against a pathologist. Nearly one third involved melanoma misdiagnosed as Spitz nevus, "dysplastic" nevus, spindle cell squamous carcinoma, atypical fibroxanthoma, and dermatofibroma. While breast biopsy claims were a close second to melanoma, when combined with breast fine-needle aspiration and breast frozen section claims, breast specimens were the most common cause of pathology malpractice claims. Cervical Papanicolaou test claims were third in frequency behind melanoma and breast; 98% involved false-negative Papanicolaou tests. Forty-two percent of gynecologic surgical pathology claims involved misdiagnosed ovarian tumors, and 85% of these were false-negative diagnoses of malignancy. The most common cause of system errors was specimen "mix-ups" involving breast or prostate needle biopsies.