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Failure to correctly read biopsy specimen

A 50-year-old woman had a digital screening mammogram. When compared to a mammogram taken five years earlier, the new mammogram revealed possible new calcifications in the central area of the left breast.

Ten days later, the patient had a routine annual mammogram that showed scattered fibroglandular tissues and a central localized group of calcifications in the left breast. Compared to the previous mammogram with faint calcifications, the new calcifications were more pronounced. The radiologist suggested a surgical consult.

The abnormal findings were discussed with the patient and her physician, who was also her employer. The next day the patient’s physician conducted an evaluation for complaints of left breast lesions. The patient was a social smoker and drinker. She reported long-term fibrocystic disease. Her family history included a mother with breast cancer who died at age 62; a maternal aunt who died of breast carcinoma in her 70s; and a female cousin who was being treated for breast cancer. The results of the physical exam were unremarkable with no definite masses noted. Due to the suspicious calcifications found on the recent mammogram, the physician ordered a left breast stereotactic biopsy.

Physician action
A week later, the patient was admitted to a local hospital for a left breast stereotactic vacuum assisted core biopsy. Pathologist A  — the defendant in this case  — read the specimen as “ductal carcinoma in situ, low nuclear grade, 0.4 cm with multiple micro calcifications” for one of the four specimens. The remaining three were found to be “benign breast tissue with micro calcifications.”  An informal consultation was obtained from Pathologist A’s colleague and noted on the pathology report. Further testing showed the specimen to be 90% positive for the estrogen receptor and 60% positive for the progesterone receptor.

A general surgeon saw the patient and noted that she had a “Strong family history of breast cancer. Needle biopsy positive for 4 mm area of low grade ductal Ca in situ.” A “needle localization with wide excision” was recommended. The surgeon recorded that the patient had decided to have bilateral simple mastectomies with reconstruction due to her strong family history of breast cancer.

A month later, the general surgeon performed a bilateral simple mastectomy and immediate postoperative breast reconstruction. Pathologist A reviewed the specimens from both breasts.

The final diagnoses were “A. right breast tissues: breast tissue, no evidence of atypia or malignancy. B. left breast issues: breast tissue with scattered microcalcifications, no evidence of atypia or residual carcinoma.”

Four weeks later, the patient went to a large metropolitan cancer center where she underwent a left breast stereotactic core biopsy. The findings indicated that the left breast showed atypical intraductal proliferation that lacked the diagnostic findings of intraductal carcinoma. Also at this visit, the specimen slides from the original core biopsy were interpreted by a pathologist with the diagnosis of atypical ductal hyperplasia (ADH) and flat epithelial atypia associated with micro calcifications. No DCIS or invasive carcinoma was detected.

A few weeks passed and the patient self-referred to the same center where she received a primary medical evaluation. The pathology reports from the bilateral mastectomies were reviewed. It was noted that there were ten outside slides from the mastectomy specimen collected and malignancy was not found in either breast. A further note was made that the initial biopsy site (that rendered the “low grade ductal Ca in situ” diagnosis) was not sampled in the sections from the simple mastectomy specimen per the pathology report. The physician’s impression was that the patient had atypical ductal hyperplasia with no ductal carcinoma in situ (DCIS) or invasive ductal carcinoma. No malignancy was found in the breast mastectomy specimen, but the prior biopsy site was not sampled.

The conclusion was made that the patient was at low risk for local recurrence after the mastectomy so radiation therapy was not indicated. An ultrasound of the axilla was ordered as a precaution to make sure there was no evidence of lymph node disease. Although the physician planned to refer the patient to an oncologist for further discussion of anti-estrogen and chemotherapy options, the patient indicated she would prefer to wait on the findings. No additional therapy or surgery was necessary.

Two further evaluations within the next eleven weeks lacked diagnostic features of intraductal carcinoma.

A lawsuit was filed against Pathologist A. The allegations included:

  • incorrectly reading and diagnosing the first stereotactic core biopsy;
  • failure to correctly and accurately identify any abnormalities in the biopsy specimens; and
  • failure to obtain a second opinion.

Legal implications
A pathologist who reviewed the patient’s medical records, but not the slides, commented that DCIS and ADH are very similar and different pathologists might decide one way or the other on this diagnosis.

Two oncologists also reviewed this case. One oncologist concluded that the patient’s decision to have a bilateral simple mastectomy was unnecessary, as there may have been no real evidence of in situ carcinoma. The second oncologist concluded that Pathologist A’s potential incorrect diagnosis of DCIS was a factor in the patient’s choice to have the bilateral mastectomy. Both physicians questioned how much information the patient was given before her decision to proceed with the surgery, as the growth rate for cancerous lesions is different for pre-menopausal and post-menopausal cancers.

A weakness in the defense of this case was that the original biopsy site was not identified during the left breast mastectomy. Thus, it was not possible to determine whether the tissues surrounding the core biopsy consisted of invasive carcinoma.

The plaintiff’s pathology expert claimed that Pathologist A should have sent the patient’s slides to another pathologist for a second opinion since the treatment for ADA/flat epithelial atypia would be different from DCIS.

The claim was settled on behalf of the pathologist.

Risk management considerations
Cases involving the diagnosis of breast cancer continue to have high frequency and severity. For that reason, pathologists may consider requesting a formal, independent opinion of a patient’s slides. The claims data from 1985 to 2010 released by the
Physicians Insurers Associations of America (PIAA) indicates the second most prevalent allegation against pathologists is diagnostic error of malignant neoplasms of the female breast. This includes cases that are unknown to be malignant or benign. (1)    

Brockway LH. Claims by specialty – A look at PIAA national closed claim data. 2011 Reporter, Vol. 5.


These closed claim studies are based on an actual malpractice claims from TMLT. These cases illustrates how action or inaction on the part of physicians led to allegations of professional liability, and how risk management techniques may have either prevented the outcome or increased the physician’s defensibility. These studies have been modified to protect the privacy of the physicians and patients.