Uterus

Uterus

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Day	POD	Histological Features
16	2	Subnuclear vacuoles (>50%), focal pseudostratification, mitosis in glands and stroma
17	3	Orderly row of nuclei, subnuclear vacuoles, rare mitotic figures
18	4	Vacuoles above and below nuclei, smaller; epical bleb; no mitosis
19	5	Decreased number of vacuoles; irregular nuclear alignment, luminar secretion, dense cellular stroma
20	6	Peak secretion; ragged luminal border
21	7	Early stromal edema; still significant secretion
22	8	Peak stromal edema; "naked" stromal nuclei
23	9	Spiral arterioles become prominent
24	10	Periarteriolar cuffing of predecidua
25	11	Predecidua beneath surface, inspissated secretions
26	12	Coalescence of decidual islands, few neutrophils
27	13	Many neutrophils, focal necrosis and hemorrhage
28	14	Prominent necrosis and hemorrhage

* Day = day in the cycle; POD = post-ovulation date.

* Don’t try to date abnormal endometrium (eg. polyp). Date on most advanced change. Generally give a 2-day range.

Grading of Uterine Stromal Sarcoma

Grading of Uterine Leiomyosarcoma

Category / Grade	Histologic Features
Mild dysplasia CIN-1	Dysplastic cells occupy the lower 1/3 of the epithelium. Occasional mitosis. Absence of abnormal mitotic figure. Koilocytosis frequently present
Moderate dysplasia CIN-2	Dysplastic cells occupy lower 2/3 of epithelium. Mitosis above basal 3-5 cell layers. Koilocytosis may still be present.
Severe dysplasia CIN-3	Dysplastic cells occupy the full thickness of the epithelium. Absence of koilocytosis. Abnormal mitotic figures is common
Definition of Dysplasia	Increased N:C ration, enlargement of cells, irregular nuclear borders, nuclear hyperchromasia, chromatin clumping, and loss of basal polarity

Grade	Category	Histologic Features
Low grade	Mild dysplasia	Reduced cytoplasmic new seen, increased nuclear-cytoplasmic ratio mitotic features (occasional), slide nuclear pleomorphism, nuclear hypochromasia nuclear polarity.
High grade	Moderate dysplasia	Mucin depletion, high nuclear cytoplasmic ratio, mitotic features, nuclear round up and loss of nuclear polarity
CIN-3	Severe dysplasia	#

Grade	Histologic Features	Note
I	Well-differentiated – tumor with prominent / easily recognizable glandular pattern and < 5% solid area.	*
II	Moderately differentiated – tumor with mixed solid and glandular pattern and 6-50% solid areas.	*
III	>50% solid or entirely undifferentiated, minimal or no gland formation.	#
Note:	Significant nuclear atypia or nuclear atypia inappropriate for architectural grade raises Grade I and Grade II tumors by one grade (see table below).	$