A 46 year old woman presented to her gynecologist with dysfunctional bleeding (DUB).

A TruTest® endometrial biopsy was performed using a Tao brush to sample the endometrium. The samples was submitted in our multifunctional fixative. Ample tissue fragments were received and were separated from the endometrial sample by filtration and submitted for histology processing in the usual manner. The remaining endometrial cytology material was processed by selective cellular enhancement technique and the slides were stained with Papanicolaou and acid hematoxylin methods.

The endometrial sample showed a small amount of proliferative endometrium with a number of dissimilar fragments consisting of severely dysplastic squamous epithelium (CIN 3) of cervical origin. (Fig 2.1) (low power H&E) and (Fig 2.2) (high power H&E). The lesion shows the classical features of squamous epithelium with a disorderly growth pattern, increased nuclear: cytoplasmic ratios, irregular nuclear membranes, increased and coarsened chromatin, and mitotic figures at all levels of the epithelium, some with abnormal configurations.

Abnormal uterine bleeding is a clinical condition with a wide differential diagnosis that includes:

• Anovulatory cycle(s)
• Endometiral polyp
• Adenomyosis
• Leiomyoma
• Endometritis
• Atrophy
• Intra-uterine contraceptive device
• Oral contraceptive use with breakthrough bleeding
• Abortion
• Ectopic pregnancy
• Endometrial hyperplasia
• Malignant tumors of endometrium or cervix
• Gestational trophoblastic disease
• Coagulopathies
• Anticoagulant drug therapy
• Severe renal or liver disease
• Thyroid disease

Although Cervical Intraepithelial Neoplasia (CIN) can cause vaginal spotting, post-coital or not; and the age distribution of High grade CIN overlaps that of DUB patients; this condition is not listed in the differential diagnosis of DUB.

his histopatholigcal differential diagnosis in this case is practically quite limited. Consideration must be given to endometrial squamous metaplasia with dysplastic features but this would almost always be seen in the context of endometrial hyperplasia, Adenocarcinoma, or adenosquamous carcinoma and would have a morular appearance, rather than contrasting strips of dysplastic squamous epithelium.

Severe squamous dysplasia of cervical origin (Cervical Intraepithelial Neoplasia, CIN 3). Proliferative endometrium with no evidence of hyperplasia, endometritis, or adenocarcinoma.

Comment: This patient had a history of abnormal pap test but this was unknown to us at the time of the examination. The case demonstrates that not all 'dysfuntional bleeding’ is of endometrial origin.

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