Is histological examination of tissue removed by general practitioners always necessary? Before and after comparison of detection rates of serious skin lesions

Objectives: To examine whether histological examination of all tissue removed by general practitioners in minor surgery increases the rate of detection of clinically important skin lesions, and to assess the impact of such a policy on pathologists' workload. Design: Before and after comparison. Setting: Stratified random sample of 257 general practitioner partnerships from the catchment areas of 19 English pathology laboratories. Subjects: Tissue removed in minor surgery by general practitioners during the control period (September 1992 to February 1993) and intervention period (September 1993 to February 1994). Intervention: General practitioners referred to their local pathology laboratory all solid tissue removed in all minor surgery, irrespective of their previous policy. Main outcome measures: Numbers of specimens referred for histology by general practitioners during intervention and control periods; numbers of primary malignant melanomas, non-melanoma malignancies, premalignant lesions, and benign lesions. Results: 257/330 partnerships participated (response rate 78%). During the intervention period 5723 specimens were sent, compared with 4430 during the control period. The referral rate increased by an estimated 1.34 specimens per 1000 patient years (95% confidence interval 0.93 to 1.76, P<0.001). General practitioners sent 204 specimens that were malignant (including 16 malignant melanomas) in the control period and 188 that were malignant (including 15 malignant melanomas) during the intervention period (change in total number of malignancies, -1.0 per 100 000 patient years (-5.9 to 3.8, non-significant). Conclusions: The intervention was associated dth a substantial increase in laboratory workload, all of which was accounted for by increases in non-serious lesions. This observation should be taken into account when considering the merits of a policy requiring histological examination in every case.