Condyloma acuminatum : its histopathological pattern

Condyloma acuminatum is one of the clinical manifestations of papillomavirus infection. The classical histopathological features are already known and do not constitute a diagnostic problem. Clinically, it has been classified into growth or proliferative, full-expression, and regressive or persistent phases, with the histopathological aspects of these distinct phases being well documented in equine cutaneous papillomas. We have designed a protocol of histopathological analysis in order to investigate the possibility of identifying the evolutional phases in human condylomata acuminata. Sixty condylomata acuminata from the files of the Department of Pathology, Universidade Federal Fluminense, were studied regarding koilocytosis, paraceratosis, acantosis, basal cell hyperplasia and mononuclear cell infiltrate. After an individual analysis and comparison of the cases, the main differential aspects of condyloma acuminatum were: koilocytosis, transepithelial lymphocytic infiltrate and basal cell hyperplasia. Thus, condylomatous lesions can be histopathologically differentiated in three major patterns: proliferative, viral replication activity and regressive.


INTRODUCTION C
ondyloma aculninatum represents one of the many clinicaI manifestations of the Human PapilIomavirus infection (HPV); it is found more frequently in the genital region and rarely in mucous membranes.1-3 Frequently associated with HPV 6 and 11, the incubation period ranges from 3 weeks to 8 months and occurs particularly in young i~dividuals.1.3Principal clinicaI consequences are transmission to sexual partners and to the fetus and newborn by infected mothers, and the risk of developing squamous cell carcinoma.3 -5 Untreated lesions can remain unchanged for 10 or more years, or more rarely, lnay regress spontaneously.2

Address for correspondence:
Eliane Pedra Dias Rua Br. de  The analysis of several biopsies from outpatient clinics in gynecology and sexual transmitted diseases (STD) allowed us to observe the differences, bath quantitative and qualitative, in the various condylomata acuminata.The growth phase, the full-expression phase, and the regressive ar persistent phase have been well characterized clinicallyY These phases were recognized histopatholagically in equine cutaneous papillomas by HAMADA et al. ll There have been no similar studies in humans.Therefore, in order to identify their differences and similarities and classify the histopathological evolutionary phases of condylomata acuminata, it is necessary to conduct a histopathological study.
Among the great number of clinicallesions associated with papillomavirus infection, only flat warts present the characteristics of spontaneous regression.Many reports have attempted to explain this phenomenon, 12-16 and most of them concurthat cell-mediated immunity is responsible for the effective regression of this kind of lesion.This immune response is expressed by an early infiltration of macrophages and T lymphocytes CD4+ in the dermis and later transepitheliaI.The non-regressing warts have an inconspicuous infiltrate composed of T lymphocytes CD8+. 17n 1993, OKABAYASHI et aI.,18 using rabbits, classified the lesions as proliferative (marked cellular proliferation) and regres,sive (inflammatory mononuclear cell infiltrate dermal and transepithelial).
In 1994, COLEMAN et aI.published their first study on the regression of genital warts in closely monitored patients.The main histopathological feature identified by COLEMAN et aI.was a marked, continuous subepithelial inflammatory infiltrate, with prominent dermal infiltration.
Based on random observations and studies on the regression phenomenon causing papillomavirus lesions, we have designed a protocol to histopathologically analyze the condylomata acuminata, aiming to identify its evolutionary phases.

MATERIALS AND METHODS
The parameters investigated in the epithelium were: koilocytosis (according to MEISELS6), basal cell hyperplasia (four or more layers of basal cells), acantosis, hyperceratosis, and paraceratosis.Histological evaIuation of the dermis included the presence and localization (dermal, basal epithelial, transepitheliaI) of mononucIear cell infiltrate.The investigation reveaIed extremely high leveIs of variation in paraceratosis and mononuclear cell infiltrate, and this resuIted in further classification according to intensity, being low, medium and high as follows: Paraceratosis low: condyloma with few areas of paraceratosis in the epithelium.
Paraceratosis medium: condyloma with some areas of paraceratosis in the epitheIium.
Paraceratosis high: condyloma with paraceratosis throughout the epithelium.
Mononuclear cell infiltrate low: condyloma with few Iymphocytes and histiocytes in few areas.
Mononuclear cell infiltrate.medium: condyloma with Iymphocytes and histiocytes, with moderate distribution, sometimes in foci or in a band-Iike pattern.
Mononuclear cell infiltrate high: condyloma with intense lymphocytes and histiocytes infiltrate, many times in a band-like pattern.
After individual analysis, the cases were grouped according to their differences and similarities in an attempt to establish an evolutionary cIassification.
We retrospectively studied 60 condylomata acuminata from the files of the Department of Pathology (UFF) from January 1994 through April 1996.The selected 60 cases fulfilled the following requirements: a) specimens measuring not less than 0.5 em in length and with sufficient dermis; and b) specimens not displaying acute inflammation.
The specimens were stained by the H.E. technique and analyzed as to the classical histopathologicaI aspects considered characteristic of condyloma acuminatuTÍ1.The detailed histopathological analysis of the cases (Fig.

4)
showed acantosis, hyperceratosis and paraceratosis in all cases, and basal cell hyperplasia in 4 (25 percent).Paraceratosis was considered mild or moderate in 25 percent of the cases and intense in 50 percent.'The lymphocytic inflammatory infiltrate was seen in all cases (mild in 69 and moderate in 31 percent).Dermis and the base of the epithelium were to the dermis and the koilocytosis; when present, it was in a concentration of five or less (Fig. 3).
Thus, according to the predominant characteristics, such as koilocytosis, transepithelial mononuclear cell inflammatory infiltrate or transepithelial inflammatory infiltrate and the absence of koilocytosis, the cases were further separated in groups A, B and C respectively.The remaining 13 lesions did not meet any of the criteria and therefore were considered as belonging to an intermediate evolutionary phase and excluded from the study.

RESULTS
The histopathological analysis of the 60 condylomata acuminata showed that koilocytosis and the mononuclear inflammatory infiltration presented the most prominent quantitative differences.
First, we selected the cases where koilocytosis -the histopathological marker of the cytopathic effect ofHPV replication -was present.The koilocyfosis "intensity varies from rare to very numerous

variation.
Group A was formed by 16 condylomata in which more than five koilocytosis (Fig. 1) per section were visible.
From the other 44 cases, for our purposes Group B, we selected 19 condylomas in which the transepithelial inflammatory infiltrate (Fig. 2) -histopathological marker of regression phenomenon -was the most prominent feature.the most frequent localization (88 percent).This group was considered as having the viral replication activity (VRA) pattern (Fig. 5).

GROUP B (n=19)
In this group, (Fig. 4) basal cell hyperplasia was detected in 32 percent.Acantosis, hyperceratosis and paraceratosis were observed in all cases.Paraceratosis was mild in 16 percent, moderate in 68 percent and intense in 16 percent.Koilocytosis was rarely seen (6 cases/32 percent).The mononuclear cell inflammatory infiltrate was localized in the dermis and epidermis, and considered mild in 32 percent, moderate in 26 percent and intense in .42percent.This was classified as Regressive (R) pattern (Fig. 6).

GROUPC(n=22)
In this group, both transepithelial inflammatory infiltrate and koilocytosis were rarely seen or were absent.The histopathological analysis of this group (Fig. 4 and paraceratosis in all cases.The paraceratosis was lTIild in 80 percent and moderate in 20 percent.Koilocytosis was less frequent (17 percent).Mononuclear cell infiltrate was absent in 33 percent, but in the remaining 8 patients lTIononuclear cell infiltrate was localized in the dermis and classified as mild.This group was considered as Proliferative (P) pattern (Fig. 7).
koilocytosis in some lesions may expIai n the negati ve results observed in studies utilizing procedures such as imlTIUnohistochemistry and/ or in situ hybridization with the aim of virus identification.Koilocytosis was diagnosed in accordance with MEISELSó criteria.The presence of a perinuclear halo, even those associated with nuclear alterations, must be carefully interpreted.In our opinion, this can not be regarded as an histopathological criterion of compatibility with HPV infection.Our results have also demonstrated the importance of koilocytosis in defining a pattern.In 31 cases classified as proliferative or regressive, it was identified in only 8 cases (26 percent -Fig.4).
Our study has delTIOnstrated the existence of a group of lesions that show histopathological characteristics that denote a lymphocyte-mediated immunological response by the patient.
The morphological regression phenomena in warts is aIready weIl d?cumented not onIy in animaIs but aIso in

DISCUSSION
The analyses of specimens from 60 patients with condylomata acuminata shows that there are quantitative histopathological differences among them.-19 0ur results are in agreement with the literature, contributing to the histopathological characterization of the regression pattern of condylomata acuminata.However, this quantitative study based only in the histopathological analysis is subjective, and its efficacy is questionable.
On the other hand, the distribution of the IYlnphocytic infiltrate is a lnore precise criteria which considers only two possibilities: its presence or absence in different sites.We believe that the best histopathological regression marker for condylomata acuminata is the transepithelial localization of the lymphocytic infiltrate.
OKABAYASHI et aI., IX studying rabbit papillolnas, characterized a proliferative phase by a marked epithelial proliferation when compared with the other phases.In our study, we characterized a group of lesions by the absence of koilocytosis and transepithelial lymphocytic infiltrate (Group C).Employing the basal cell hyperplasia criterion -the histopathological expression of proliferation in squamous cell epitheliuln -we were able to verify its presence in all Group C cases (Fig. 4), and in 25 and 32 percent of group A and B cases, respectively.This expressed difference was a major criteria for classifying Group C as representative ofthe proliferative pattern which probably corresponds to the early phase ofHPV infection.
Acantosis and hyperceratosis were present in all cases and for this reason they were not considered as particular criteria for a,ny group.Paraceratosis was also observed in alI cases.However, it was inconspicuous in the proliferative pattern and marked in the activity pattern, showing a clear relationship between the cytopathic effect of HPV and the disturbance in squamous celI differentiation (Fig. 4).
Prior studies have primarily emphasized the clinicaI variations of condylomata acuminata, and secondarily the identification of the virus by different technological methods based on immunopathology and lnolecular biology.2J.7.xOur study resulted in three distinct patterns of condyloma cUlninatuln: proliferative, viraI replication acti vity and regressi ve.These patterns probably retlect the biological phase of the HPV infection: one phase of interference in the control of epithelium proliferation, another phase of an intense viraI replication with cytopathic effects expression and finally, a phase characterized by the regression ofthe action ofthe HPV, possibly in answer to the host defense.
These biological phases are probably linked to the clinicaI expression phases.However, it is possible that the duration of each phase depends on an efficient ilnmune response.An accurate histopathologic study of condylolna acuminatulTI, besides improving the precise diagnosis of lesions not presenting koilocytosis, permits the identification of the histopathologicaI pattern.The correlation of this pattern with the evolution tilne of the lesion and the recurrence history could give the physician a prognostic evaluation based on the patient's own current defenses.
Group C was formed by 12 condylomas in which the inflammatory infiltrate was absent or lnild and confined DIAS, E.P.; ANA LUISA FIGUEIRA GOUVÊA,A.L.F.; EYER, C.C -Condyloma \ PC-M PC-A K lI-L II-M lI-A II-D II-B II-T II-Abs BH = Basal Hyperplasia AC = Acantosis HC Hyperceratosis

Figure 4 -
Figure 4 -Percentages relative to the various histopathological aspects identified in: