554 J Clin Pathol 1990;43:554-559 Adenoacanthoma of the endometrium: morphological changes induced by human J Clin Pathol: first published as 10.1136/jcp.43.7.554 on 1 July 1990. Downloaded from papillomavirus W F Kealy, P G Annis, J A Barry, J M Hogan Abstract With this in mind, we reviewed the sections of The observation of koilocyte-like all uterine carcinomas received in this features in the squamous epithelium of laboratory over 12 years and attempted to some endometrial adenoacanthomas establish the presence of HPV in those with a prompted an investigation into a pos- squamous component. sible viral aetiology. These changes closely resemble those that occur in the ectocervical mucosa which are accepted Methods as morphological evidence of human Sections of hysterectomy specimens removed papillomavirus (HPV) infection. Sec- for endometrial carcinoma between 1977 and tions of 87 hysterectomy specimens 1988 inclusive were re-examined for the removed for endometrial carcinoma presence of a squamous component. The oc- over 12 years, together with preoperative currence of squamous epithelium of benign curettings, were reviewed for the histological appearance intimately mingling presence of acanthomatous change and with the tumour, however small in amount, for appearances suggestive ofHPV infec- was accepted as evidence of acanthomatous tion. The ages of the women ranged from change. Note was also taken of epithelial 36 to 84 years, average age 62-6. Light changes which might be ascribed to HPV microscopical examination showed infection, such as cytoplasmic vacuolation and koilocytosis, papillary formations, and koilocyte-like change. Sections of cervix, intranuclear eosinophilic inclusions when present, were also reviewed for similar of both squamous and glandular epi- epithelial appearances and for the presence of thelium in some tumours. Immunocyto- squamous metaplasia. Preoperative endo- chemistry and DNA in situ hybridisation metrial curettings were also re-examined. indicated the presence of HPV antigen in In two hysterectomy specimens showing http://jcp.bmj.com/ squamous and glandular cells, and peri- adenoacanthoma of the endometrium multiple nuclear virus particles characteristic of circumferential blocks of the total cervix were HPV were seen on electron microscopi- taken, which extended from the ectocervix to cal examination in those cells with the lower uterine cavity, to ascertain whether nuclear inclusions. there was a direct connection between cervical HPV probably infects endometrial metaplastic epithelium and the endometrium. adenocarcinomas directly from the Immunohistochemistry for HPV was perfor- on September 25, 2021 by guest. Protected copyright. cervix but it is unlikely that it has an med on sections of 23 adenoacanthomas and aetiological role. It is possible, however, the accompanying cervix, and six endometrial that in addition to being a "passenger," curettings were also included. An immuno- the virus may stimulate squamous peroxidase method using a polyclonal anti- metaplasia in some adenocarcinomas of papillomavirus antibody was used followed by the endometrium and may also exert visualisation with an avidin-biotin complex some influence on their behaviour. detection system (Dako). DNA in situ hy- bridisation for HPV was applied to sections of adenoacanthoma in 11 cases using biotiny- Adenoacanthoma of the endometrium is a lated probes specific for HPV types 6/1 1, malignant epithelial tumour composed of both 16/18, and 30/50. (Enzo diagnostics). glandular and squamous elements in which In two instances the hysterectomy specimen the squamous component is histologically was received fresh and unfixed and multiple benign."I The squamous parts of the tumours random blocks of the endometrial carcinoma are considered to arise as a result of meta- were taken into glutaraldehyde for electron plastic glandular cells,"' but there is little microscopical examination. Selected areas of Department of agreement about the amount of squamous formalin fixed, paraffin wax embedded blocks Histopathology, epithelium which should be present before an of endometrial adenoacanthomas were also Regional Hospital, adenocarcinoma may be called an adenoacan- Wilton, Cork, Ireland reprocessed for ultrastructural examination. W F Kealy thoma.'1'7 We have been impressed by the P G Annis fact that the squamous epithelium present in J A Barry uterine adenoacanthomas often displays cyto- Results J M Hogan plasmic vacuolation and koilocyte-like Eighty seven hysterectomy specimens of Correspondence to: Dr W F Kealy changes, the appearances of which resemble endometrial carcinoma were received into this Accepted for publication those produced by human papillomavirus laboratory over the study period. Endometrial 5 April 1990 (HPV) infection of ectocervical epithelium. curettings before hysterectomy were sent for Adenoacanthoma of the endometrium 555 examination in 63 cases. Squamous epithelium intranuclear inclusions were seen in some ofthe was identified in sections of endometrial squamous cells ofa small number ofcurettings. adenocarcinoma in 50 hysterectomy cases, 46 ofwhich showed acanthomatous change (fig 1), IMMUNOHISTOCHEMISTRY J Clin Pathol: first published as 10.1136/jcp.43.7.554 on 1 July 1990. Downloaded from four were examples of adenosquamous carci- This technique for HPV showed positive stain- noma. Koilocyte-like changes of the squamous ing in sections from 13 hysterectomies and one epithelium were present in 28 adenoacan- endometrial curetting. The staining was dis- thomas (fig 2). These cellular changes occurred tributed in a rather focal manner, of varying both superficially and deeply within the intensity, and in places affected both the tumours. Keratinisation was not a feature of nucleus and cytoplasm of both squamous and the squamous epithelium and multinucleation glandular epithelium. No cytological features was rarely seen. In places the squamous and accounted for the variability of staining but the glandular cells adopted a rather papillary pat- squamous epithelium tended to stain more tern. Round, relatively large, faintly eosino- intensely than the glandular cells. The intra- philic nuclear inclusions were seen focally in nuclear inclusions, however, tended to stain both glandular and squamous epithelium (figs more darkly in the glandular epithelium (fig 5). 3 and 4). Metastases from some of the endo- Sections ofcervix showed focal staining of both metrial carcinomas also showed focal benign glandular and squamous cells. This positivity, squamous epithelium and occasionally however, was not often accompanied by similar koilocyte-like changes. staining of the endometrium and indeed, the Four of the accompanying cervices showed a converse was more usual. Immunoperoxidase deficiency of ectocervix. Of the remaining 42, staining of a single ovarian metastasis with 20 showed squamous metaplasia of the endo- squamous metaplasia was negative. cervical epithelium. Microscopic examination of sections of the multiple circumferential DNA IN SITU HYBRIDISATION blocks taken from the whole cervix in the two In sections of endometrial adenoacanthoma cases showed focal squamous metaplasia, but from 11 cases five tumours were negative for direct extension of the squamous epithelium to HPV. Three showed strong focal positivity for the uterine cavity was not seen. Koilocytic all the viral subtypes. The remaining three change in the ectocervical epithelium was were negative for subtype 6/1 1; of these, present in 13 cases and of these, 10 also showed however, one showed positive staining of some squamous metaplasia. Intranuclear inclusion squamous cells for subtype 16/18 and another bodies of the type seen in the endometrium for 31/35/51. The third showed positivity of were not present in either the ectocervical or occasional squamous and glandular cells for endocervical epithelium. Preoperative endo- subtypes 16/18 and 31/35/51, respectively. The metrial curettings were performed in 32 instan- probe tended to stain the intranuclear in- ces in those patients with adenoacanthoma. clusions only weakly but outlined the peri- http://jcp.bmj.com/ Seventeen of these showed acanthomatous nuclear area rather intensely (fig 6). In com- change of which 12 had koilocytic features mon with most endometrial adenoacanthomas, suggestive of HPV infection. Eosinophilic those tumours showing positive immunohisto- Figure 1 Adenoacanthoma of endometrium showing on September 25, 2021 by guest. Protected copyright. benign squamous epithelium. 556 Kealy, Annis, Barry, Hogan Figure 2 Adenoacanthoma of endometrium showing koilocyte-like change of squamous epithelium J Clin Pathol: first published as 10.1136/jcp.43.7.554 on 1 July 1990. Downloaded from (Haematoxylin and eosin.) Figure 3 Glandular epithelium with nuclear inclusions (Haematoxylin and eosin.) http://jcp.bmj.com/ on September 25, 2021 by guest. Protected copyright. chemistry and DNA in situ hybridisation were from paraffin wax blocks. Examination of the all well differentiated carcinomas. nuclear inclusions showed that they consisted of fibrillary and granular material, the fibrils of ELECTRON MICROSCOPY which ranged from 5 to 10 nm in thickness and Ultrastructural examination of the glutaralde- there was peripheral displacement of nuclear hyde fixed samples showed few of the light chromatin. Intranuclear viral particles were microscopic features suggestive of viral infec- not identified. Many cells, however, contained tion, as described above. Appearances very perinuclear aggregates