Australian Society of CytologyCase of the Month
July 2004 - Answer and Discussion
Endometrial adenocacinoma.
Answer
Cytology
Numerous malignant cells consistent with adenocarcinoma of the endometrium are present in a heavily bloodstained background.(fig1)
Abnormal cells occur singly and in small groups. Many exhibit
vacuolation and degenerative changes. Chromatin clearing and prominent nucleoli are features of higher grade tumours. The severity of malignant nuclear features varies with the grade of tumour.(figs 2,3)
A watery, granular background of diathesis is also noted.(fig4)
Histology
Endometrial curettings show a poorly differentiated endometrial adenocarcinoma. The tumour is of mixed epithelial type. The predominant component is uterine papillary serous carcinoma with a smaller degree of endometrioid grade 3 carcinoma.(fig5)
Immunocytochemistry studies show the tumour is made up of approximately 80% serous carcinoma and 20% endometrioid carcinoma. The p53 marker (fig6) stains the high grade serous component and oestrogen receptor markers are expressed in the low grade endometrioid component.(fig7)
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| fig 5 | fig 6 | fig 7 |
Discussion
In the absence of any hormone replacement therapy, bleeding and the presence of endometrials in the smear of a post menopausal woman should set the screener’s alarm bells ringing.
As described above, the smears exhibit the classic cytomorphological appearance of endometrial adenocarcinoma. However, grading and tumour typing is done histologically on nuclear and architectural features.
Endometrial adenocarcinomas often have mixed patterns of differentiation and non-endometrioid (e.g. Serous adenocarcinoma) and endometrioid types can occur together.
The predominant papillary serous adenocarcinoma component is a high grade variant of endometrial carcinoma which can resemble its ovarian cousin with its very large pleomorphic tumour cells. It is an aggressive tumour with a poor prognosis and will spread to the peritoneum more readily than endometrioid tumours.
Endometrioid carcinomas are the most common cancers of the endometrium. The endometrioid grade 3 carcinoma is the poorly differentiated form (grade 1 = well diff’) of the tumour and exhibits marked nuclear pleomorphism but little glandular differentiation.
References:
- Gray W,McKee G,Diagnostic Cytopathology, 2nd Edition,Churchill Livingstone 2003.
- Geisinger K,Raab S,Stanley M,Silverman J,Abati A, Modern Cytopathology, Churchill Livingstone 2004.
- Demay R, Practical principles of Cytopathology, ASCP Press 1999.
- Cibas E, Ducatman B, Cytology, Diagnostic principles and clinical correlates, 2nd Edition, Elsevier 1996.
