Motivation for developing the Szalay Cyto-Spatula

(Excerpt from the book CYTOLOGY OF THE UTERINE L. Szalay)

None of the methods used during recent decades to obtain material for the cytological smear of the cervix uteri has uniformly established itself, because none offers 100 percent reliability in the detection of pre-stage cervical cancer.

1. Endocervical changes

The ectocervix can be easily evaluated with the naked eye and, especially, with the colposcope. Obtaining substance from the surface of the portio offers therefore no particular difficulties. In contrast, the majority of the endocervix is not visible with a colposcope. Collection of cytological material is only possible to the extent that the cotton applicator is able to enter the cervix and cervical canal. During the last 2 decades, the local treatment of pathological changes of the ectocervix has found wide acceptance (electro-coagulation, cryotherapy, laser treatment, portio grafting). The squamocolumnare transition zone, which is the decisive area for the development of cervical carcinoma, is often located in an endocervical postion. The cervical intraepithelial neoplasia is therefore endocervical origin in 15 – 20% of cases. This means that early detection is possible neither with a colposcope nor with the classic cytological methods of obtaining substance.

During the years 1979 – 1987 we examined over 600 cone biopsies, in which the cervical intraepithelial neoplasia or invasive carcinoma originated in the endocervix in 15% of cases.

This anatomical localisation also explains the incidence of advanced cervical carcinoma in women who have undergone regular yearly coloscopic, cytological and gynaecological screening examinations. In these cases, the presentation of a rapidly progressive carcinoma is inconclusive, because during the conventional screening of the epithelium, the endocervix was only partly included.

2. The upper epithelial layers inhibit the collection of representative cytological material

Hyperkeratosis

The classic cytological methods of obtaining substance collect spontaneously exfoliated cells from the superficial layers of the epithelium. Special dyes (Krutsay) prove that in a significant number of severe dysplasia, carcinomata in situ and invasive carcinoma, the Dierks keratinisation zone forms a thick hyperkeratotic layer. This impedes the spontaneous exfoliation of the tumour cells lying in the deeper layers and represents an unassailable barrier for conventional instruments, making the collection of tumour cells impossible.

Parakeratosis

Many cervical intraepithelial neoplasiae show a parakeratosis of the upper layers. These cells are spontaneously exfoliated; however the tumour cells located in the lower layers are not gathered by the collection instrument.

Necrosis

Disorders of the blood supply and metabolism in the superficial layers of invasive carcinoma lead to degeneration and necrosis. This necrosis layer inhibits the collection of cells from the carcinoma areas located beneath it. This explains the many false negative cytological findings in the case of invasive carcinomas. Adenocarcinomas show an even more pronounced tendency to rapid autolysis and necrosis. The surfaces of the cervical adenocarcinoma, which are anyway mainly endocervical in origin, are covered in mucus and necrotic substances. This explains why the conventional methods of collecting material so rarely give a diagnosis of endocervical adenocarcinoma.

3. Normal Epithelium

Lower layers of cervix- and cervical polyps can already have been infiltrated by a malign tumour, while still displaying a normal epithelium on the surface. In cases such as these, the spontaneously exfoliated cells are always normal. Non-epithelial tumours of the cervix, such as sarcomas or metastatic cervical tumours can only be reached by cytological methods if the superficial squamous or cylinder epithelial layer is completely perforated so that tumour cells reach as far as the surface.