Histological types of cervical cancer

The World Health Organisation (WHO) recognises two main histological types of invasive cancer

• Squamous carcinoma (which constitute about 85% of all cases)
• Adenocarcinoma (which constitute about 10-12% of all cases)

Several other  types of  carcinoma eg adenosquamous carcinoma, adenoid cystic  carcinoma, metastatic carcinoma make up the remaining 3-5%of all cases.

Squamous carcinomas are further typed according  to whether they are keratinising or   non keratinising carcinomas. Keratinising carcinomas may be well differentiated  or moderately differentiated and are composed of large tumour cells. The non keratinising carcinomas (poorly differentiated carcinomas) may be of large cell or small cell type.

Adenocarcinomas are less commonly found and  although each type is histologically distinct it is not uncommon for  two or more histological forms of adenocarcinoma to be present in a single tumour .The frequent cooexistence of glandular  and squamous carcinoma suggest that they may have a common origin in the reserve cells of the cervix as well as a common aetiology. The most frequent type of adenocarcinoma to be found in the cervix is the endocervical type of mucinous adenocarcinoma. Three grades of  endocervical carcinoma are recognised -well differentiated, moderately differentiated and poorly differentiated - depending on the similarity of the tumour cell to the glandular  epithelial lining of the endocervix.

Invasive keratinizing squamous cell carcinoma (histology). Groups of cancer cells (->) invade stroma in which inflammatory cells are visible.	Invasive well differentiated squamous cell carcinoma (histology). A high power view of a cluster of cancer cells. Note keratinization of tumor cells in the centre (->).	Invasive well differentiated squamous cell carcinoma (histology). A high power view of a cluster of cancer cells. Note nuclear morphologic features of malignancy and mitosis (->).

 

Nonkeratinizing invasive squamous cell carcinoma (histology).	Adenocarcinoma of cervix -  well differentiated (histology). Note tumor cells are forming glands .The glands are crowded and penetrate beyond the stroma of the cervical epithelium into the fibromuscular wall of the cervix. The tumour cells lining the glands are abnormal  showing loss of polarity of the nuclei which are large , hyperchromatic and irregular. Mitotic figures are often present

 

Histological types of carcinoma found in cervix (WHO classification) Squamous cell carcinoma (epidermoid carcinoma) Keratinising (well differentiated and moderately differentiated) non keratinising (large and small cell types) Spindle cell carcinoma Adenocarcinoma  endocervical type Variant : adenoma malignum (minimal deviation carcinoma) Variant :villoglandular papillary  adenocarcinoma Endometrioid adenocarcinoma Clear cell adenocarcinoma Serous adenocarcinoma Mesonephric adenocarcinoma Intestinal type (signet ring) adenocarcinoma Other epithelial tumours Adenosquamous carcinoma Adenoid cystic carcinoma Small cell carcinoma Undifferentiated carcinoma  Metastatic tumours (breast, ovary, colon, and direct spread of endometrial carcinoma)