Reducing False Negatives in Endometriosis Histology Through Deeper Sections

How diagnostic accuracy in peritoneal biopsies could be optimized?

Key Points

Highlights :

• Deeper level tissue sections increased the diagnostic rate of endometriosis by 6.7%, reducing false-negative diagnoses in cases with scant endometriotic foci on initial sections.

Importance :

• Accurate diagnosis of endometriosis is critical for effective treatment, yet false-negative results from initial histologic evaluations pose a challenge.
• This study highlights the potential of deeper tissue sectioning to improve diagnostic accuracy, reducing missed cases and enhancing patient care

What's done here :

• The authors investigated the diagnostic value of deeper tissue sections in cases with suspected endometriosis but no diagnosis on initial histologic sections.
• They compared diagnostic rates between initial tissue sections and deeper levels using the WHO essential criteria.
• They also quantified the increase in diagnostic yield and resource utilization associated with deeper tissue sampling.

Key features :

• Clinically the study highlights the need to consider deeper tissue sections to minimize false negatives, especially in resource-intensive diagnostic settings.
• Deeper sections reduced false negatives, and identified an additional 6.7% of endometriosis cases, raising the diagnostic rate from 73.3% to 80%.
• Achieving the increased diagnostic yield required an average of 9.8 slides per diagnosis.

Potential limitation of the study :

• Three deeper levels of paraffin blocks were used in this study which is the default number of levels obtained for most tissues in their setting. This raises an unanswered question on the optimal number of deeper level sections.

Lay Summary

A group of researchers led by gynecopathologist Professor Joseph Rabban has published their findings in the International Journal of Gynecological Pathology, evaluating the diagnostic utility of deeper tissue sections in biopsies from patients with suspected endometriosis.

The definitive diagnosis of endometriosis relies on histopathologic examination of biopsied tissue. Interestingly, the diagnostic yield of histopathologic confirmation in clinically suspected peritoneal biopsies ranges from 51% to 89.5%.

In some cases, small ectopic endometrial tissue foci in peritoneal biopsies may go undetected, resulting in “false-negative” reports. This may be due to superficial sectioning of paraffin-embedded tissue blocks.

In this retrospective study, researchers examined biopsies from 135 patients at an academic institution (UCSF, California, USA). Initial paraffin block sections confirmed endometriosis in 73.3% of cases (99/135). However, deeper sectioning of the paraffin blocks identified endometrial tissue in an additional 9 cases, increasing the diagnostic rate to 80% (108/135).

Accurate diagnosis of endometriosis is critical for counseling, long-term medical and surgical management, and assessing the risk of endometriosis-associated tumorigenesis.

This study underscores the importance of deeper level sections in cases where initial histopathology fails to confirm the diagnosis. Pathologists are encouraged to request deeper sections in tissues with a presumptive clinical diagnosis of endometriosis, ensuring no diagnostic findings are overlooked.

Research Source: https://pubmed.ncbi.nlm.nih.gov/39475364/