Leiomyoma 2026-10-31
The principal modes are growth within the uterine wall, towards the cavity, and towards the outer surface: intramural uterine fibroids, submucosal uterine fibroids and subserosal uterine fibroids. “Fibrous tumour” is the historical label; the usual modern lesion is a leiomyoma, a benign growth of smooth muscle with a variable connective-tissue component, rather than a mass of collagen alone.[ref]
An intramural uterine fibroid enlarges within the myometrium. It can remain enclosed by uterine muscle, push the cavity aside, or expand both inner and outer contours. Several nodules can give an irregularly enlarged uterus. Expansion compresses surrounding tissue into a cleavage plane or pseudocapsule; this differs from the destructive infiltrative growth typical of a malignant lesion.
A submucosal uterine fibroid grows towards the endometrium, projecting into and distorting the uterine cavity. It may remain broad-based or acquire a stalk as the surrounding wall is displaced. A pedunculated uterine fibroid can be pushed through the cervical canal and appear in the vagina as a uterine polyp. A polyp formed in this way is a mode of presentation of the same smooth-muscle tumour, not necessarily a different histological species. Its relation to the cavity helps explain why a comparatively small lesion may be associated with substantial bleeding.
A subserosal uterine fibroid projects outwards beneath the serosal covering. It may have a broad attachment or a long pedicle and become a large extrauterine-looking mass. Lateral outward growth can extend between the layers of the broad ligament; cervical growth can displace neighbouring pelvic structures. Rarely, a detached pedunculated lesion gains a blood supply from adjacent tissues and persists as a parasitic growth; this is not ordinary distant metastasis.[ref]
Uterine Fibroids by Merck Manual Professional Edition. Anatomical locations: intramural, submucosal, subserosal, cervical, intraligamentous and parasitic forms
The three directions are not mutually exclusive: a large nodule may affect both the uterine cavity and its external surface. Modern location classifications describe its relation to endometrium, myometrium and serosa more precisely, but those later type numbers are unnecessary to explain the anatomical modes requested here.
Growth is also distinct from secondary change. A poorly supplied area can undergo hyaline or cystic degeneration, haemorrhagic change or calcification; these changes alter consistency without establishing a new malignant mode of growth. Uterine fibroids often respond to the reproductive hormonal environment and commonly shrink after menopause, but neither every lesion's course nor its rate of growth is identical.[ref]
Uterine Leiomyomata in StatPearls. Etiology, histopathology and secondary changes; hormone-related growth and postmenopausal involution
Location and attachment describe the mode of expansion; tissue examination establishes the nature of the tumour.Resuscitate significant haemorrhage while identifying its cause; pregnancy, timing in relation to birth, and the condition of the uterus determine the definitive treatment. A vaginal loss need not originate in the uterus, and the visible volume may underestimate concealed bleeding. Assess consciousness, pulse, blood pressure and ongoing loss; serious bleeding calls for urgent obstetric or gynaecological help, intravenous access, blood sampling and access to blood transfusion. Investigations must not delay control of a life-threatening source.
Outside pregnancy, distinguish excessive menstrual bleeding from irregular, postcoital or postmenopausal bleeding. Causes include uterine fibroids, endometrial polyps, disturbed ovulation, coagulopathy and cancer. A speculum examination may reveal a cervical or vaginal source. History, examination, blood count, and appropriately selected ultrasonography, hysteroscopy or tissue sampling establish the cause. Current treatment for heavy menstrual bleeding may use tranexamic acid or hormonal treatment where suitable; removal of a polyp or treatment of a uterine fibroid addresses a structural cause. Suspected cancer needs a diagnostic and specialist pathway, rather than repeated empirical suppression of bleeding.[ref]
Heavy menstrual bleeding by NICE. NG88, investigation according to history and examination, and cause-directed treatment
In early pregnancy, consider threatened or established miscarriage and retained pregnancy tissue. Establish the location and viability of the pregnancy with ultrasonography and, where appropriate, serial human chorionic gonadotropin measurements. Stable cases permit a choice among expectant, medical or surgical management according to the diagnosis and circumstances; heavy ongoing bleeding or instability changes the urgency. An ectopic pregnancy may cause vaginal bleeding together with dangerous internal haemorrhage, even though the bleeding pregnancy is outside the uterus. Pain, collapse or instability therefore demands urgent assessment rather than an assumption that all bleeding represents a harmless menstrual or uterine event.[ref]
Ectopic pregnancy and miscarriage by NICE. NG126, §§1.3–1.7: emergency assessment, diagnosis and management
Later pregnancy requires distinction between placenta praevia, placental abruption and other genital-tract sources. Placenta praevia may cause heavy painless bleeding; placental abruption may involve pain, a tense uterus and concealed loss. Stabilise the mother, assess the fetus and locate the placenta by ultrasonography. Avoid a digital examination that could disturb a covering placenta before placenta praevia has been excluded. The timing and route of birth depend on severity, placental position, gestation and maternal and fetal condition. A placenta covering the cervical opening usually requires Caesarean section; the diagnosis is not an instruction to apply a vaginal plug and wait through major continuing loss.[ref]
Placenta praevia, placenta accreta and vasa praevia by RCOG. Bleeding, ultrasound assessment and planning birth
[ref]Antepartum haemorrhage by RCOG. Green-top Guideline 63, §7.3: digital examination precaution
During and after birth, organise postpartum haemorrhage causes as poor uterine contraction, retained tissue, genital-tract trauma and defective clotting. A uterine rupture is a surgical emergency; a contracting uterus does not exclude a traumatic source. For uterine atony, uterine massage and a suitable uterotonic accompany resuscitation; emptying a distended urinary bladder may help contraction. Examine for tears and repair them; deal with retained placental tissue with skilled obstetric care, and do not forcibly detach an abnormally adherent placenta. Correct relevant coagulopathy and use blood products as indicated. Current early treatment includes tranexamic acid within the recommended interval. Continuing bleeding may require balloon tamponade or surgery; a uterine inversion requires urgent skilled replacement and resuscitation, not treatment as simple atony. Delayed bleeding after birth suggests retained tissue or infection and requires renewed assessment.[ref]
Consolidated guidelines for the prevention, diagnosis and treatment of postpartum haemorrhage by the World Health Organization (2025). First-response treatment bundle and cause-directed management of refractory bleeding
An 1864 practitioner could recognise miscarriage, abnormal placental attachment or separation, retained placenta, atony and traumatic bleeding, and could attempt pressure, manual measures and delivery appropriate to the cause. Cold applications and vaginal plugging appeared in period practice, but were not interchangeable cures. Contemporary obstetric discussion already distinguished several mechanisms of bleeding.[ref]
Quarterly Report on Midwifery (April 1864). pp. 549–556: uterine disease, pregnancy and obstetric complications
In particular, a uterotonic cannot repair a tear, and obstructing the outflow does not establish that internal haemorrhage has ceased. The modern diagnostic and resuscitative measures above explain why treatment must follow the mechanism rather than the symptom alone.Classify the bleeding by anatomical source and by its relation to pregnancy, childbirth and menstruation; treatment must address that source. The amount of visible genital haemorrhage does not measure all the loss: a ruptured ectopic pregnancy or concealed placental abruption can cause major internal blood loss. Initial assessment of severe bleeding concerns the circulation, anaemia and the need for resuscitation while the cause is established. Bleeding from the urethra or rectum must first be distinguished from genital bleeding.
Local sources outside the uterine cavity. The vulva and vagina may bleed from lacerations after childbirth or other trauma, an inflamed lesion, a foreign body, a vascular lesion or cancer. Examination localizes the loss; treatment is local compression and repair of a significant laceration, removal of the foreign body, cause-directed treatment of infection, or specialist management of the lesion. A cervical polyp, cervical ectropion, cervicitis or cervical cancer can cause bleeding from the cervix, often noticed between periods or after intercourse. A suitable polyp can be removed and examined; inflammation requires its cause to be established, while a suspicious lesion requires diagnostic assessment rather than indiscriminate cauterization. After menopause, thin, fragile vulvovaginal tissues can also bleed; this does not remove the need to investigate a suspicious lesion. These are different conditions, not one disease called “uterine haemorrhage”. [ref]
Vaginal Bleeding by Merck Manual. Etiology, examination and cause-directed treatment of vulvar, vaginal and cervical bleeding
Bleeding from the endometrium. Heavy or irregular menstruation may accompany ovulatory dysfunction, uterine fibroids, endometrial polyps, adenomyosis, a coagulopathy, medication effects or endometrial cancer. Modern assessment includes the menstrual and drug history, a full blood count, and selected ultrasound, hysteroscopy or tissue sampling according to the suspected cause. Where appropriate, menstrual bleeding can be reduced with tranexamic acid or hormonal treatment; an intracavitary polyp or uterine fibroid may instead need targeted removal. Persistent postmenopausal bleeding must not simply be treated as an ordinary period. [ref]
Heavy menstrual bleeding by NICE. NG88 §§1.2–1.5: assessment, blood count, selected investigation and medical or surgical treatment
Early pregnancy. A miscarriage may bleed while pregnancy tissue separates or remains in the uterus. In a stable, confirmed case, expectant, medical or surgical management may be appropriate; heavy continuing loss or infection changes the urgency. Ectopic pregnancy requires a separate plan: selected stable cases may be monitored or treated medically, but rupture with haemorrhagic collapse requires urgent operative control, not treatment of the vagina as though it were the principal source. A hydatidiform mole is another pregnancy-related source of abnormal bleeding; current management includes removal by suction evacuation and subsequent human chorionic gonadotropin surveillance for persistent disease. [ref]
Gestational Trophoblastic Disease Treatment by NCI. Hydatidiform moles: bleeding, evacuation and biochemical follow-up
[ref]Bleeding During Pregnancy by ACOG. Early pregnancy loss, ectopic pregnancy and the distinction between vaginal and internal bleeding
[ref]Ectopic pregnancy and miscarriage by NICE. NG126, management of tubal ectopic pregnancy and diagnostic precautions
Later pregnancy and labour. Placenta praevia commonly produces relatively painless bleeding, whereas placental abruption more often causes pain and uterine tenderness; these are useful patterns, not infallible rules. Management depends on the mother's circulation, the fetus, the placental lesion and the stage of pregnancy, with urgent delivery when required. A blind digital cervical examination is inappropriate before a possible placenta praevia has been excluded. Ruptured vasa praevia causes fetal rather than maternal bleeding and demands a different interpretation. A small blood-stained mucous “show” during cervical change is not equivalent to these pathological losses. [ref]
Antepartum Haemorrhage by the Royal College of Obstetricians and Gynaecologists. Green-top 63, history, examination and management; exclusion of placenta praevia before digital examination
[ref]After delivery. The principal categories are failure of uterine contraction, retained placental tissue, trauma and disordered coagulation. For uterine atony, the aim is to restore contraction with uterine massage and an appropriate uterotonic. Retained tissue, a genital laceration or uterine inversion requires correction of that particular cause; a coagulopathy requires haemostatic support. With placenta accreta spectrum, attempted forcible separation can provoke severe haemorrhage. Current care combines resuscitation with cause-directed measures, and can require tranexamic acid, balloon tamponade, embolisation or surgery when initial measures fail. Later postpartum bleeding also raises retained tissue and endometritis. [ref]
Heavy bleeding after birth by RCOG. Causes and treatment, including retained placenta, uterine contraction, trauma and escalation
The 1865 distinction. An answer of the period could distinguish menstrual loss, local lesions, pregnancy-related haemorrhage and post-delivery failure of contraction through the history and physical examination. Compression, local plugging, removal of an accessible lesion and obstetric intervention were among the available approaches; their use was debated. The 1864 discussion of placenta praevia documents such disagreement. Modern imaging, blood banking, the present drug regimens and current operative pathways must not be attributed to that practice. Nor should historical astringents or depletion be substituted for identifying the source. [ref]
Midwifery in the Edinburgh Medical Journal (September 1864). pp. 262–268, discussion of placenta praevia and competing methods of management