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Non tumor

Dysfunctional uterine bleeding (DUB)

Reviewer: Nat Pernick, M.D. (see Reviewers page)
Revised: 27 November 2011, last major update November 2011
Copyright: (c) 2002-2011, PathologyOutlines.com, Inc.

Clinical features

Definition: bleeding >5 days of unknown cause in women of childbearing age (eMedicine #1, #2); a clinical term, not a pathologist term
Known causes: adenomyosis, anovulatory cycle, chronic inflammation, drugs with hormonal side effects, ectopic pregnancy, endocrine disorder, endometrial carcinoma (5-15% of postmenopausal bleeding), endometrial hyperplasia, endometrial polyp (5-15%), endometriosis, exogenous hormones, idiopathic stromal predecidualization in postmenopausal women, leiomyoma, luteal phase defect, malnutrition, obesity, ovarian granulosa-theca tumor, precocious puberty, pregnancy complication
● May be due to degenerative changes in uterine blood vessels associated with atrophy
● Can classify based on ovulatory or non-ovulatory cycles:

● If patient ovulates, may be due to inadequate proliferative phase, inadequate secretory phase, irregular shedding or membranous dysmenorrhea
Inadequate proliferative phase: disparity between clinical menstrual cycle date and microscopic changes (usually delayed morphologic changes of proliferation)
Inadequate secretory phase: discrepancy of 2+ days between microscopy and clinical cycle date; biopsy shows underdeveloped secretory endometrium or secretory and proliferative endometrium in same specimen; also irregular shedding; due to low progesterone; associated with infertility, amenorrhea; treat with hormones
Irregular shedding: bleeding 7+ days due to lag in shedding of secretory endometrium, which is normally completed by day 4 of menstruation; should do biopsy on day 5+ of menstruation; biopsy shows retained secretory endometrium, fragmented menstrual endometrium, proliferative endometrium; occurs in 10-17% of DUB cases; associated with luteal phase defect
Membranous dysmenorrhea: rare, endometrial cast passed during menstruation, resembles decidua; may be due to exogenous progesterone

Anovulatory cycle: proliferative endometrium during chronological secretory phase; usually causes endometrial hyperplasia


● If other causes are ruled out, progesterone plus reassurance; optional therapy includes mid-cycle estrogen (mid-cycle bleeding), and late-cycle progestin (late-cycle bleeding), combined high-dose estrogen and high-dose progestin
● Treatment goals are to stop bleeding, replace iron loss, prevent future bleeding

Micro description

● Fibrin clumps in endometrial stroma (not present in normal menstrual stroma), stromal crumbling (fragmented pieces with dense stromal cellularity)
● Exogenous hormones cause predecidual stroma, edema and wimpy tubular glands of different sizes
● Plasma cells are common if focal stromal breakdown is present, but this likely represents a physiologic process, not infection (Hum Pathol 2007;38:581, but see Mod Pathol 2001;14:877)

Micro images

Endometrial curette of perimenopausal bleeding of hormonal effect: characteristic atrophic glands and decidualized stroma

End of Uterus > Non tumor > Dysfunctional uterine bleeding (DUB)

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