Table 1.

Influence of core needle biopsy number and core index on agreement between preoperative and postoperative histopathology

	Number of cores				Core index
	N	Median	Range	p Value	Median	Range	p Value
Type
Agree	78	3	1–7	0.415	161	15–1260	0.331
Disagree	35	2	1–5		144	20–760
Grade
Agree	67	2	1–5	0.172	153	20–812	0.190
Disagree	46	3	1–7		151	15–1260
Mitoses
Agree	66	2	1–4	0.300	145.5	20–812	0.148
Disagree	47	3	1–7		171	15–1260
Tubule formation
Agree	60	3	1–7	0.738	145.5	15–1260	0.983
Disagree	53	2	1–5		160	20–812
Pleomorphism
Agree	64	3	1–7	0.615	152	42–1260	0.530
Disagree	49	2	1–4		153	15–660

In total, 113 patients were examined to find out whether the number of cores collected during the diagnosis of a suspicious lesion correlated with the likelihood of agreement between preoperative and postoperative histology. This was assessed by two methods: (1) a count of the number of cores and (2) an index of the amount of material examined by the pathologist (as described in Patients and methods). Mitoses, tubule formation, and nuclear pleomorphism were components of tumour grade. The p value was determined by binary logistic regression.