COLPOSCOPY & GYNECOLOGIC LASER SURGERYVolume 3, Number 2, 1987Mary Ann Liebert, Inc., PublishersPp. 87-92

Transformation Zone: Genesis and Classification

O. EDUARDO TALLEDO and DONALD G. GALLUP

ABSTRACT

The degree of abnormality of the transformation zone was graded based on well-estab-lished parameters: surface contour, clarity of demarcation of abnormal features, abnor-mal vessels, punctation, and white epithelium. Six hundred patients were studied. Forgrading purposes, only patients who subsequently had either a conization or hysterec-tomy were considered. The grading system seems a practical means to forecast the prob-able histologie abnormality as well as an excellent modality in the teaching of colposcopy.

INTRODUCTION

The value of colposcopy in the evaluation of patients with abnormal Pap smears is now well es-

tablished. Along with cytology and appropriate biopsy material, it contributes to the detectionand managment of preclinical cancerous lesions and early invasive cancer.'1"3' The standardizationof terminology used to describe the normal and abnormal colposcopic findings in the transforma-tion zone has contributed greatly to its popularity among American gynecologists.'4' However, a

systematic classification of abnormal findings has not been widely accepted.'5"7' Our experiencewith a grading system of abnormalities of the transformation zone at the Medical College ofGeorgia is presented.

MATERIALS AND METHODS

The records of 600 patients seen in the colposcopy clinic for abnormal Pap smears were reviewed.Abnormal colposcopic findings were matched with histologie diagnoses made in specimens obtainedby either conization or hysterectomy (Table 1). A grading system for abnormalities found in thetransformation zone was developed and tested in the study population (Table 2). Punctation was

classified as fine or course, white epithelium as whitish, thick white, or waxy pearl thick white, andmosaic as flat or faint and well defined. These classifications are not included as separate items inTable 1. Poor demarcation of abnormal findings was used to indicate diffuse borders or faint fea-tures. The most severe colposcopic feature was used to assign the grade of abnormality of the trans-formation zone.

Department of Obstetrics and Gynecology, Section of Gynecologic Oncology, Medical College of Georgia,Augusta, Georgia.

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Table 1. Correlation between Colposcopy and Histology (137 Patients)Final histologie diagnosis3

Colposcopic findingsMild Moderate Severe Microinvasive Invasive

dysplasia dysplasia dysplasia CIS carcinoma carcinoma Otherb

Normal 1 5 3 1Punctation 7 13 10 13 3Mosaic 6 14 11 9 2

Atypical vessels 1 Ie 2 2White epithelium 11 29 13 11 3Increased ICD 2 4 6 1

Good demarcation 5 6 1Poor demarcation 2 9 5 3Uneven surface contour 1 19 2

4

6

6

9

3

24

aCone, hysterectomy.bChronic cervicitis.cCx Bx CIS.

Table 2. Abnormal Transformation Zone

Grade ISmooth surface3Normal or whitish epitheliumFlat or faint mosaicFine punctationICD may be increasedPoor demarcation of abnormal features

Grade IISmooth or uneven surfaceWhite, thick epitheliumWell-defined mosaicPunctation, course

Grade IIIUneven surfaceWaxy pearl, thick, white epitheliumAtypical vesselsGood demarcation of abnormal featuresGrade I or II abnormalities may or may not be present

aSlight irregularity may be present due to endocervical epithe-lium or nabothian cysts.

TRANSFORMATION ZONE: GENESIS AND CLASSIFICATION

Initially, biopsies were taken of each colposcopic finding for histologie correlations. Schematicchanges of typical and atypical transformation zones are depicted in Figures 1 and 2. Pathologicdiagnoses were used as they appeared in the original report.

RESULTS

Of the 600 patients evaluated for abnormal Pap smears, 137, or 22.6%, had either conization or

hysterectomy. The distribution of grades of abnormal transformation zones is seen in Table 3.Grade I was encountered in inflammatory as well as in dysplastic lesions with minor degrees ofatypia. Grades II and III signaled more severe abnormalities, particularly Grade III, emphasizingthe findings of abnormal vessels, waxy pearl thick white epithelium, and surface irregularity as indi-cators of significant pathology. In this study group, unsatisfactory colposcopy was found in 13% ofthe patients. Only 1 patient, who had an invasive cancer, was not diagnosed preoperatively. Colpo-scopically, she had a giant condyloma, which was corroborated by several biopsies. The cancer wasfound at the base of the condyloma after hysterectomy.

DISCUSSION

The transformation zone is the area containing metaplastic epithelium, both typical and atypical.Distally, it is limited by native squamous epithelium; proximally, by columnar epithelium.

It would appear that the process of metaplasia in the majority of women will result in the develop-ment of new squamous epithelium of different degrees of maturity and a typical transformationzone. Colposcopically, whitish epithelium is usually found at the original squamous columnar junc-tion, decreasing gradually toward the periphery, with no sharp borders against the normal squa-mous epithelium.'9' Flat, ill-defined mosaiclike arrangements of vessels, particularly around glandorifices, hairpin capillaries, which at times resemble a fine punctate, nabothian cysts, and branchingvessels complete the normal colposcopic findings of benign squamous metaplasia. The acidity of thevaginal pH probably triggers the process of metaplasia.

FIG. 1. Metaplastic squamous epithelium replaces the villi of the columnar epithelium. The capil-lary architecture of the villi is displaced by the metaplastic process and is indistinguishable from theangioarchitecture of normal squamous epithelium. Corresponding colposcopic findings are indi-cated. Left: Before application of acetic acid. Right: After application of acetic acid.

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FIG. 2. Abnormal epithelium grows in irregular blocks surrounded by punctate or mosaic vessels.Abnormal colposcopic findings are indicated. Left: Before application of acetic acid. Right: Afterapplication of acetic acid.

The initial or dynamic phase occurs predominantly in the fetus, adolescence, and first preg-nancy.'81 Coppleson and Reid"1 have demonstrated that young metaplastic cells in vitro possessphagocytic properties. During this dynamic process, if a mutagen (e.g., virus, chemical, sperm) be-comes operative, a process of atypical metaplasia may ensue. Course punctate, well-defined mosaic,and white epithelium translate the abnormal findings. With more severe atypical changes (CIS, in-vasive cancer), proliferation of the abnormal epithelium and neovascular formation take place (Fig.2). Colposcopically, waxy pearl thick white epithelium, abnormal vessels, and irregular surface pat-terns become the dominant features. From the foregoing, one can anticipate that different colpo-scopic pictures have the same histologie substrate. As noted by Schaetzing'101 of South Africa, the

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TRANSFORMATION ZONE: GENESIS AND CLASSIFICATION

Table 3. Correlation between Colposcopy and Histology (137 Patients)Final histologie diagnosis*

Atypical-transformation Mild Moderate Severe Microinvasive Invasive

zone dysplasia dysplasia dysplasia CIS carcinoma carcinoma Otherh

Grade I 20 34 10 1= 20

Grade II 2 4 9 1

Grade III 3 4 13 1

Unsatisfactory 11 13

aCone, hysterectomy.bChronic and acute cervicitis, squamous metaplasia, condyloma, and so on.cInvasive carcinoma originating at the base of giant condyloma acuminatum.

colposcopic picture depends on the time the mutagen enters the cell. Punctation results early inmetaplasia before fusion of the papillae takes place. Somewhat later, after partial fusion, mosaic de-velops. If the mutagen is operative in late metaplasia, when most of the papillae are connected,white epithelium end result. Since typical and atypical metaplasia are usually incomplete and of dif-ferent age, a great deal of experience is required to recognize which colposcopic features are associ-ated with the most severe pathologic changes. Stafl and Mattingly'11' and Cruickshank et al.'12'have reported a close correlation between colposcopy and histology when assessing the severity ofthe lesion. Recently, Sakuma et al.'13' have documented that the degree of whiteness of the atypicaltransformation zone correlates with the degree of abnormality found in the histologie specimen.Grading should prove useful in this regard, since it provides a practical means to categorize degreesof abnormalities of the transformation zone. Grading also pinpoints areas with the most likely se-

vere histologie changes. In addition, grading is a practical educational tool in the teaching of colpos-copy. Table 3 underlines the value of colposcopy and reminds us of a few patients who tax even themost skillful observer.

In our experience, the squamous-squamous junction (original squamous columnar junction) isoften confused with the new squamous columnar junction. A colposcopy that should have beentermed inadequate is, therefore, a source of disappointment when a cone or hysterectomy specimenreveals a significantly worse pathology than was anticipated. Branching vessels of ectopy are a

source of confusion for the young house officer and probably explain the patients who, in spite ofhaving grade III changes, ultimately displayed a relatively benign histology.

REFERENCES

1. BOLTEN, K.A. (1967). Practical colposcopy in early cervical and vaginal cancer. Clin. Obstet. Gynecol.10, 808-837.

2. CHANEN, W., and HOLLYOCK, V.E. (1974). Colposcopy and the conservative management of cervicaldysplasia and carcinoma in situ. Obstet. Gynecol. 43, 527-534.

3. HILL, E.C. (1966). Preclinical cervical carcinoma, colposcopy and the "negative" smear. Am. J. Obstet.Gynecol. 95, 308-319.

4. SCHMITT, A.W. (1978). In: Cervical Pathology and Colposcopy. Burghardt, E., Holzer, E., and JordanJ.A. (eds.). Stuttgart, George Thieme, pp. 30-31.

5. COPPLESON, M., PIXLEY, E. and REID, B. (1978). Colposcopy, 2nd ed. Springfield, 111, Charles CThomas, pp. 133-134.

6. HASEGAWA, T., SAKUMA, T., KIGUCHI, K., et al. (1981). Colposcopic grading and features of the

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colposcopic findings in microinvasive carcinoma, in: Proceedings of the Fourth World Congress of the In-ternational Federation of Cervical Pathology and Colposcopy. Anderson, M.C. (ed.). London, IFCPC,pp. 154-157.

7. KOLSTAD, P. (1981). Report of the Colposcopic Nomenclature and Grading Committee, in: Proceedingsof the Fourth World Congress of the International Federation for Cervical Pathology and Colposcopy.Anderson, M.C. (ed.). London, IFCPC, pp. 170-171.

8. KOLSTAD, P., and STAFL, A. (1981). Atlas of Colposcopy, 3rd ed. Baltimore, University Park Press,p. 64.

9. COPPLESON, M., and REID, B. (1975). Origin of premalignant lesions of cervix uteri, in: Progressin Gy-necology, Taymor, M., and Green, T. (eds.). New York, Grune & Stratton, Vol. 6, pp. 517-539.

10. SCHAETZING, A.E. (Quoted by STAFL, A., 1983.) Contemp. Obstet. Gynecol. pp. 85-104.11. STAFL, A., and MATTINGLY, R.F. (1973). Colposcopic diagnosis of cervical neoplasia, Obstet. Gyne-

col. 41, 168-176.12. CRUICKSHANK, D.P., KAMINSKY, D.B., and EKBLADH, L.E.V. (1976). Colposcopic evaluation of

cervical intraepithelial neoplasia. J. Reprod. Med. 17, 327-330.13. SAKUMA, T., HASEGAWA, T., TSUTSUI, F., and KURIHARA, S. (1985). Quantitative analysis of the

whiteness of the atypical cervical transformation zone. J. Reprod. Med. 30, 773-776.

Address reprint requests to:O. Eduardo Talledo, M.D.

Director, Section of Gynecologic OncologyMedical College of Georgia, CK-166

Augusta, GA 30912

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