Occasionally a patient with a cytology or biopsy diagnosis of high grade dysplasia will have a "negative" cervical cone biopsy. This apparent discrepancy needs to be investigated so that an explanation can be found.
Possible explanations:
(1) specimen mix-up with the first specimen
(2) specimen mix-up with the second specimen (less likely)
(3) overdiagnosis of the first specimen
(4) presence of a small focus of high grade dysplasia that was totally excised by the first procedure
(5) the focus of dysplasia is not included in the biopsy (located further up the endocervical canal)
(6) failure to completely examine the entire cone (not all of the tissue embedded, tissue poorly embedded, deeper sections required)
(7) an inadequate or incomplete cone biopsy
(8) problem preparing or labeling the slides
Each possibility needs to be considered, usually starting with items 3, 4 and 6. If these pan out then the other explanations need to be considered.
The occurrence of this situation can often be reduced by:
(1) a system that minimizes specimen mix-ups
(2) extra care taken with the diagnosis of high grade dysplasia in cytology or biopsy specimens, with peer review and supportive immunostains (like p16)
(3) proper technique in obtaining the cone
(4) careful submission of the entire specimen with the margins inked
(5) proper slide preparation
