Utility of Additional Tissue Sections in Surgical Pathology.

Background: To avoid diagnostic errors such as missed diagnosis and errors in staging tumors due to inadequate tissue sampling, pathologists submit additional sections (AS).

Objective: This study assessed frequency, diagnostic yield, distribution, and cost of AS.

Method: Among 1542 AS cases, we calculated mean AS per case; fraction of AS that altered diagnosis or stage; AS variation by tissue, malignant versus benign lesions, presence or absence of neoadjuvant therapy, mass, margin, lymph nodes, or other source, resident versus pathologist assistant (PA) dissector; and AS cost per case.

Results: Overall 9.2 ± 8.8 AS were collected per case. In only 3.8% (58/1542) of cases AS altered diagnosis or stage. Urinary bladder cases provoked the most AS: 19.5 ± 15.1 per case. Significantly more AS came from malignant versus benign lesions (10.8 ± 9.7 vs 7.6 ± 7.5, P = <.0001) and from specimens treated with neoadjuvant therapy versus malignant lesions not so treated (12.3 ± 9.4 vs 10.3 ± 9.8, P = .02). Lymph nodes were sampled more heavily compared with mass, margin, and other sites combined (11.8 ± 11.4 vs 8.9 ± 8.4, P = .003), but in 78.4% (1209/1542) of cases, AS were from mass. Of diagnosis or stage altering AS cases, two thirds (38/58) were from masses, one fifth (11/58) from lymph nodes, a 10th (6/58) from margins, and a 20th (3/58) from other specimen sites. Resident versus pathologist assistant dissection caused no significant AS difference. AS contributed 40% cost per case.

Conclusions: AS per case ranged widely; their diagnostic yield was low; they were highest in urinary bladder specimens, in malignant and particularly neoadjuvant-treated lesions. Although lymph nodes were most heavily sampled, most AS were from masses. Resident dissection did not increase AS and cost of AS was high.