The borderline cervical smear: colposcopic and biopsy outcome

Aims-To review the outcome of women referred with smears showing borderline nuclear change (BNC), and to determine any differences in outcome if BNC w as persistent, preceded by dyskaryosis, or followed treatment for cervical intraepithelial neoplasia (CIN). In addition, to determine criteria that mi ght permit delineation of a BNC subtype, predictive of CIN. Methods-The records of 178 women referred for colposcopy in 1993, with last smear showing BNC, were obtained from our laboratory database. The cytolog y, colposcopy, and biopsy follow up for a five year period were also obtain ed. The patients were divided into three categories according to their smea r status before the last referral borderline smear: category 1, persistent BNC (n = 39); category 2, BNC preceded by dyskaryotic smears (n = 100); and category 3, BNC after treatment for CIN (n = 39). The referral borderline smears were reviewed on cases with negative outcome and those with a biopsy diagnosis of CIN2 and CIN3. Results-In 50 women (28%) no biopsy was deemed necessary after colposcopic assessment. The biopsy results in the remaining 128 (72%) women were as fol lows: normal in 18 (10%), koilocytosis in 12 (7%), CIN1 in 45 (25%), CIN2 i n 32 (18%), and CIN3 in 21 (12%) women. High grade lesions (CIN2, CIN3) wer e seen on biopsy in 14 of 39, 33 of 100, and six of 39 cases in category 1, category 2, and category 3, respectively. Blind review of the referral bor derline smears from 53 women with a biopsy diagnosis of high grade lesions (32 CIN2, 21 CIN3) confirmed they were borderline in 23, upgraded them to m ild dyskaryosis in 15, and found that 14 cases of isolated moderate or seve re dyskaryotic cells had been missed originally. The borderline change was in mature squamous cells in five of 23 and in immature metaplastic epitheli um in 18 of 23 cases. After smear review in 68 women with negative outcome, 36 smears were reclassified as negative in keeping with inflammation and a trophy, three were considered unsatisfactory, one was upgraded to CIN1, and 28 were confirmed as BNC. Of the latter, 25 of 28 were in mature squamous cells. The five year follow up on women with negative colposcopy (n = 50), negative loop excision of transformation zone (LETZ) (n = 18), and LETZ wit h koilocytosis (n = 12) showed subsequent high grade CIN on LETZ in 16, 0, and two patients, respectively. Conclusions-On referral of women for colposcopy with last smear showing BNC , the outcome was high grade CIN in over 30% of cases, irrespective of whet her the borderline smear was preceded by another borderline smear or by a d yskaryotic smear. In contrast, in those referred because of BNC after treat ment of GIN, high grade CIN was seen less frequently (15% of cases). Furthe rmore, in cases that necessitated loop excisions, high grade CIN was seen i n 41%. This study also showed that BNC associated with inflammation or atro phy, or BNC in mature squamous cells, appears to have lower predictive valu e for CIN than those cases where BNC is associated with immature metaplasti c epithelium. The use of terms such as "BNC favour reactive" for the former and "BNC favour dyskaryosis" for the latter is recommended, together with follow up by cytology and colposcopy, respectively.