BASIC INFORMATION

Date & Time: 2024-10-26 16:32:00 Indian Standard Time

Lecture Handout Prepared from the Teaching Session by: Dr. R. K. Mishra

SUMMARY

This lecture provides a comprehensive overview of uterine leiomyomas (fibroids), covering their fundamental pathophysiology, classification, clinical features, secondary changes, and management strategies. The content explains that fibroids are benign, monoclonal, hormone-dependent tumors originating from myometrial smooth muscle cells. The session details the pathophysiological mechanisms of local hyperestrogenism, including increased estrogen receptor density and local aromatase activity. It provides a thorough explanation of the FIGO classification system (Types 0-8) and discusses special variants like parasitic and broad ligament fibroids. Clinical features are explored, emphasizing that most fibroids are asymptomatic, but when symptomatic, menorrhagia is the most common presentation due to increased endometrial surface area and impaired uterine contractility. Secondary changes, particularly red degeneration in pregnancy, are detailed along with their management. The lecture presents a systematic approach to differential diagnosis, comparing fibroids with adenomyosis and endometrial polyps. Management principles are outlined, from expectant management for asymptomatic cases to a tiered medical and surgical approach for symptomatic patients, including hysteroscopic, laparoscopic, and abdominal myomectomy, as well as uterine artery embolization.

KEY KNOWLEDGE POINTS

• Basic Science: Uterine fibroids are benign, monoclonal, hormone-dependent smooth muscle tumors with a characteristic whorled appearance and pseudocapsule.

• Pathophysiology: Fibroids create a local hyperestrogenic state via increased estrogen receptors, reduced estradiol (E2) to estrone (E1) conversion, and local estrogen synthesis via aromatase.

• Classification: The FIGO classification system (Types 0-8) provides a standardized method for describing fibroid location relative to the endometrium and serosa.

• Clinical Features: Fibroids are most often asymptomatic. If symptomatic, menorrhagia is the most common feature. Pain is uncommon.

• Secondary Changes: Hyaline degeneration is the most common secondary change. Red degeneration is an aseptic infarction seen in pregnancy and is managed conservatively. Sarcomatous change is rare (<0.5%).

• Differential Diagnosis: Key differentiators for fibroids, adenomyosis, and endometrial polyps based on clinical features, uterine characteristics, and imaging findings.

• Management Principles: Asymptomatic fibroids are managed expectantly. Symptomatic management depends on fibroid type, location, and patient factors, following a tiered approach from medical therapy (first and second-line) to surgical intervention.

• Surgical Options: Fertility-sparing options include myomectomy (hysteroscopic, laparoscopic, abdominal). Uterine artery embolization is a minimally invasive alternative.

INTRODUCTION

Uterine leiomyomas, or fibroids, are the most prevalent benign tumors of the female genital tract, arising from the smooth muscle cells of the myometrium. Despite their benign nature, fibroids represent a significant clinical entity, contributing to considerable morbidity through symptoms such as abnormal uterine bleeding, pelvic pain, pressure symptoms, and reproductive dysfunction. Understanding their epidemiology, pathophysiology, classification, and clinical manifestations is fundamental for accurate diagnosis, patient counseling, and the formulation of appropriate management strategies. This lecture aims to provide a clear, evidence-based understanding of the basic science, clinical context, and management of uterine fibroids for postgraduate trainees.

LEARNING OBJECTIVES

• Define uterine fibroids and describe their pathological characteristics, hormonal dependence, and epidemiology.

• Accurately classify uterine fibroids using the FIGO system and differentiate them from adenomyosis and endometrial polyps.

• Explain the pathophysiological mechanisms responsible for the clinical features of fibroids, particularly menorrhagia.

• Formulate a management plan for both asymptomatic and symptomatic fibroids, outlining the indications for medical and surgical interventions.

• Recognize the secondary changes in fibroids, particularly red degeneration, and describe their clinical management.

CORE CONTENT

1. Basic Pathology, Epidemiology, and Pathophysiology

1.1. Tumor Nature and Characteristics

• Origin: Uterine fibroids are benign neoplasms originating from the smooth muscle cells of the myometrium. They are monoclonal tumors, meaning each fibroid arises from a single mutated progenitor cell.

• Appearance: On gross examination, a transected fibroid displays a characteristic whorled appearance. They are typically surrounded by a pseudocapsule composed of compressed adjacent myometrial tissue, which creates a surgically important cleavage plane.

1.2. Epidemiology

• Prevalence: Fibroids are the most common benign solid tumors and pelvic tumors in women, affecting up to 80% of women by age 50.

• Age of Onset: The peak incidence of clinically significant fibroids is within the reproductive age group, specifically between 35 and 45 years of age.

1.3. Hormonal Influence and Pathophysiology

The growth of uterine fibroids is critically dependent on estrogen and progesterone. They tend to grow during the reproductive years and regress after menopause. Fibroids create and sustain a local hyperestrogenic microenvironment through three key mechanisms:

• Increased Estrogen Receptor Density: Fibroid cells have a higher concentration of estrogen receptors than normal myometrial cells.

• Altered Estrogen Metabolism: They inhibit the conversion of potent estradiol (E2) to weaker estrone (E1), maintaining a high local concentration of active estrogen.

• Local Estrogen Synthesis: Fibroid tissue contains the enzyme aromatase, which facilitates the local conversion of androgens to estrogens, creating a self-perpetuating growth cycle.

2. Risk and Protective Factors

2.1. Risk Factors

• Race/Genetics: Women of African descent have a significantly higher incidence. A woman with a first-degree relative with fibroids has an approximately 2.5 times greater risk.

• Nulliparity: Women who have never carried a pregnancy to term are at increased risk due to prolonged, uninterrupted hormonal cycles.

• Early Menarche: Extends the lifetime exposure to estrogen.

• Obesity: Adipose tissue is a primary site of peripheral aromatization of androgens to estrogens.

• Diet and Alcohol: Consumption of red meat and alcohol are associated with increased risk.

• Hormonal Contraceptives: Long-term use of oral contraceptive pills (OCPs) can be a risk factor for the initial development of fibroids, but not for the growth of existing ones.

2.2. Protective Factors

• Increased Parity: Multiparity is protective, as each pregnancy provides a "break" from cyclical hormonal stimulation.

• Smoking: Paradoxically, smoking is a protective factor. Nicotine and other components inhibit the aromatase enzyme, reducing peripheral estrogen conversion.

• Menopause: The decline in ovarian hormone production leads to fibroid regression.

3. Genetic and Chromosomal Abnormalities

Approximately 40% of fibroids are associated with specific chromosomal abnormalities, including:

• Translocation between chromosomes 12 and 14: t(12;14)

• Deletion of chromosome 7

• Trisomy 12

• Mutations in the HMGA2 and MED12 genes.

4. Classification of Leiomyomas

4.1. Traditional and FIGO Classification

All fibroids originate as intramural growths and may subsequently grow toward the endometrial cavity (submucous) or the serosal surface (subserous). The International Federation of Gynecology and Obstetrics (FIGO) system provides a more precise classification.

• Submucous:

  • Type 0: Pedunculated, entirely intracavitary.

  • Type 1: Sessile, with <50% intramural component.

  • Type 2: Sessile, with ≥50% intramural component.

• Other:

  • Type 3: 100% intramural, but contacts the endometrium.

  • Type 4: Entirely intramural, with no contact with endometrium or serosa.

  • Type 5: Subserous, with ≥50% intramural component.

  • Type 6: Subserous, with <50% intramural component.

  • Type 7: Pedunculated subserous.

• Atypical:

  • Type 8: Atypical locations (e.g., cervical, parasitic).

  • Hybrid Fibroids: Large fibroids that transgress from submucosal to subserosal, designated with two numbers (e.g., Type 2-5).

4.2. Special Variants

• Broad Ligament Fibroids:

  • True: Originates de novo from smooth muscle within the broad ligament itself.

  • Pseudo: A subserous fibroid that grows secondarily between the leaves of the broad ligament. Associated with polycythemia due to potential ureteric compression and increased erythropoietin.

• Parasitic (Wandering) Fibroids: A pedunculated subserous fibroid (Type 7) that detaches and implants elsewhere in the abdomen, deriving a new blood supply.

5. Clinical Features

• Asymptomatic Presentation: This is the most common clinical scenario.

• Abnormal Uterine Bleeding (Menorrhagia): The most common symptom. Mechanisms include:

  • Increased Endometrial Surface Area: Due to distortion of the uterine cavity.

  • Impaired Uterine Contractility: Fibroids disrupt the "living ligature" function of the myometrium, preventing effective constriction of spiral arterioles.

  • Surface Ulceration: Primarily with submucous fibroids.

• Pelvic Pain: An uncommon symptom. When present, it may be due to dyskinetic uterine contractions, degeneration, torsion of a pedunculated fibroid, or rare sarcomatous change.

• Pressure Symptoms: Depend on fibroid size and location (e.g., urinary frequency from bladder compression, constipation from rectal compression, dyspnea from diaphragmatic compression).

• Infertility: An infrequent cause (~3% of cases), typically due to cavity distortion or tubal occlusion.

• Anemia and Fatigue: Secondary to chronic menorrhagia.

6. Secondary Changes in Fibroids

• Hyaline Degeneration: The most common type of degeneration.

• Red Degeneration (Carnous): An acute aseptic infarction most commonly seen during pregnancy. It presents with fever, pain, and leukocytosis. Management is strictly conservative with analgesia and antipyretics.

• Cystic Degeneration: Most frequent in postmenopausal women.

• Calcific Degeneration: Calcium deposition, often in subserous fibroids, creating a "womb stone." Calcification begins at the periphery.

• Sarcomatous Change (Malignant Transformation): The least common change (<0.5%), with the highest risk in postmenopausal women with a rapidly growing mass.

7. Differential Diagnosis: Fibroid vs. Polyp vs. Adenomyosis

8. Management of Uterine Leiomyomas

8.1. Management of Asymptomatic Fibroids

• Expectant Management: The standard approach is periodic monitoring with TVS every 6-12 months.

• Contraindications: Active intervention is required for suspected sarcomatous change, torsion, unexplained infertility, or rapid growth.

8.2. Management of Symptomatic Fibroids

• Submucous Fibroids (Type 0 & 1): Hysteroscopic myomectomy is the treatment of choice.

• Intramural & Subserosal Fibroids: A tiered approach is used.

  • First-Line Medical Therapy (Symptom Control): For controlling menorrhagia. These do not reduce fibroid size.

    • Oral Contraceptive Pills (OCPs)

    • Progestin-Releasing IUDs (e.g., Mirena)

    • Tranexamic Acid

  • Second-Line Medical Therapy (Size Reduction): Used if first-line fails or for bulk symptoms. These induce a hypoestrogenic state to shrink fibroids.

    • GnRH Agonists (e.g., Leuprolide): Continuous administration causes pituitary downregulation.

    • GnRH Antagonists (e.g., Cetrorelix): Directly block GnRH receptors.

    • Aromatase Inhibitors (e.g., Letrozole)

    • Anti-progestins (e.g., Mifepristone)

8.3. Surgical Management

• Myomectomy (Fertility-Sparing):

  • Laparoscopic Myomectomy: For uterine size <17 weeks and <5 fibroids.

  • Abdominal Myomectomy (Laparotomy): For larger or more numerous fibroids.

• Uterine Artery Embolization (UAE): An interventional radiology procedure where particles are injected to occlude uterine arteries, causing fibroid ischemia and necrosis. Reduces volume by ~50% and controls bleeding in ~90% of cases.

SURGICAL PEARLS

• The presence of a pseudocapsule provides a crucial dissection plane for enucleation during myomectomy.

• All fibroids, regardless of final location, begin as intramural growths.

• Fever and leukocytosis are key features distinguishing red degeneration from torsion of a fibroid in a pregnant patient.

• A symmetrically enlarged, tender, globular uterus in a perimenopausal woman is highly suggestive of adenomyosis, not a fibroid.

• Intermenstrual bleeding with a normal-sized uterus should raise high suspicion for an endometrial polyp.

COMPLICATIONS AND THEIR MANAGEMENT

• Torsion: Torsion of a pedunculated subserosal fibroid is an acute surgical emergency causing severe pain without fever or leukocytosis, requiring immediate operative intervention.

• Obstetric Complications: Fibroids in pregnancy increase the risk of spontaneous abortion, preterm labor, malpresentation, abruptio placentae, and postpartum hemorrhage (PPH) due to uterine atony.

MEDICOLEGAL AND PATIENT SELECTION CONSIDERATIONS

• Myomectomy During Cesarean Section: This is strongly contraindicated for intramural or subserous fibroids due to the extreme risk of uncontrollable hemorrhage. The only exception may be an easily accessible pedunculated subserosal fibroid.

• Pre-Myomectomy Assessment: It is imperative to perform a semen analysis for the male partner before proceeding with a myomectomy for infertility. A finding of severe male factor infertility may negate the primary indication for uterine preservation and requires thorough patient counseling.

• Informed Consent: Patients managed expectantly must be counseled on the importance of follow-up and warning signs (e.g., rapid growth).

• Sarcoma Suspicion: A rapidly growing uterine mass in a postmenopausal woman must be investigated with a high index of suspicion for leiomyosarcoma.

SUMMARY AND TAKE-HOME MESSAGES

• Uterine fibroids are common, benign, hormone-dependent myometrial tumors, most of which are asymptomatic and managed expectantly.

• Symptomatic fibroids most often cause menorrhagia due to increased endometrial surface area and impaired myometrial contractility.

• The FIGO classification is the standard for describing fibroid location and guiding management, with hysteroscopic myomectomy being ideal for Type 0 and 1 submucous fibroids.

• Red degeneration in pregnancy is an aseptic infarction managed conservatively; myomectomy during pregnancy or cesarean section is contraindicated.

• Management is individualized, progressing from medical therapies (to control symptoms or reduce size) to surgical options like myomectomy or UAE.

MULTIPLE CHOICE QUESTIONS (MCQs)

1. Uterine fibroids originate from which cell type?

   a) Endometrial stromal cells

   b) Perimetrial cells

   c) Myometrial smooth muscle cells

   d) Cervical epithelial cells

2. According to the FIGO classification, a pedunculated fibroid located entirely within the uterine cavity is:

   a) Type 0

   b) Type 1

   c) Type 7

   d) Type 8

3. The most common clinical presentation of uterine fibroids is:

   a) Menorrhagia

   b) Pelvic pain

   c) Infertility

   d) Asymptomatic

4. Which mechanism contributes to the local hyperestrogenic state within a fibroid?

   a) Increased conversion of estradiol (E2) to estrone (E1)

   b) Downregulation of estrogen receptors

   c) Local conversion of androgens to estrogens via aromatase

   d) Systemic inhibition of progesterone

5. A 30-year-old woman in her second trimester of pregnancy presents with acute abdominal pain, fever, and leukocytosis. A known fibroid is present. What is the most appropriate management?

   a) Immediate myomectomy

   b) Administration of broad-spectrum antibiotics

   c) Conservative management with analgesics and antipyretics

   d) Termination of pregnancy

6. Which of the following is considered a protective factor against the development of uterine fibroids?

   a) Obesity

   b) Nulliparity

   c) Early menarche

   d) Smoking

7. A 48-year-old woman presents with a symmetrically enlarged, globular, and tender uterus not exceeding 14 weeks in size. She complains of severe dysmenorrhea. What is the most likely diagnosis?

   a) Large intramural fibroid

   b) Endometrial polyp

   c) Adenomyosis

   d) Subserous fibroid

8. The primary therapeutic goal of first-line medical agents like OCPs and tranexamic acid is to:

   a) Reduce the size of the fibroid

   b) Prevent sarcomatous transformation

   c) Control heavy menstrual bleeding

   d) Induce a hypoestrogenic state

9. What is the primary reason for avoiding myomectomy for an intramural fibroid during a cesarean section?

   a) Increased risk of infection

   b) Risk of massive, uncontrollable hemorrhage

   c) Prolonged operative time

   d) Difficulty in uterine closure

10. Which type of fibroid is most commonly associated with torsion?

    a) Intramural

    b) Submucous

    c) Pedunculated subserosal

    d) Cervical

11. A "feeder vessel sign" on Doppler ultrasound is characteristic of:

    a) An intramural fibroid

    b) Adenomyosis

    c) An endometrial polyp

    d) A calcified fibroid

12. A fibroid that is 100% intramural and contacts the endometrium without protruding into the cavity is classified as:

    a) Type 1

    b) Type 2

    c) Type 3

    d) Type 4

13. What is the approximate risk of sarcomatous transformation in a uterine fibroid?

    a) < 0.5%

    b) 1-2%

    c) 5%

    d) 10%

14. Continuous administration of a GnRH analog like Leuprolide is used in fibroid management because it causes:

    a) A sustained surge in FSH and LH

    b) Downregulation of pituitary GnRH receptors and a hypoestrogenic state

    c) Upregulation of progesterone receptors

    d) Direct apoptosis of myoma cells

15. What is the most common type of secondary degeneration seen in fibroids?

    a) Red degeneration

    b) Cystic degeneration

    c) Calcific degeneration

    d) Hyaline degeneration

16. A key investigation to perform for the male partner before a myomectomy for infertility is:

    a) Blood group analysis

    b) Karyotyping

    c) Semen analysis

    d) Hormonal profile

17. Polycythemia is a rare systemic finding most characteristically associated with which fibroid variant?

    a) Pedunculated submucous fibroid

    b) Parasitic fibroid

    c) Broad ligament fibroid

    d) Cervical fibroid

18. A patient has a fibroid with 70% of its volume located within the myometrium and 30% protruding into the endometrial cavity. What is its FIGO type?

    a) Type 1

    b) Type 2

    c) Type 3

    d) Type 5

19. The concept of a "living ligature" in the uterus refers to the ability of myometrial fibers to:

    a) Support the pelvic organs

    b) Contract and constrict blood vessels to control bleeding

    c) Facilitate sperm transport

    d) Enclose and encapsulate a fibroid

20. A patient on expectant management for an asymptomatic fibroid reports that her abdomen is enlarging rapidly. What is the most crucial action?

    a) Reassure her that this is normal

    b) Switch her to first-line medical management

    c) Advise immediate surgical evaluation for potential malignancy

    d) Schedule a follow-up ultrasound in 12 months

Answer Key: 1(c), 2(a), 3(d), 4(c), 5(c), 6(d), 7(c), 8(c), 9(b), 10(c), 11(c), 12(c), 13(a), 14(b), 15(d), 16(c), 17(c), 18(b), 19(b), 20(c)

MOTIVATIONAL MESSAGE FROM DR. R. K. MISHRA

The pursuit of surgical excellence demands more than skilled hands; it requires a mind sharpened by relentless learning and a conscience guided by unwavering compassion. Each case is a sacred trust.

My best wishes are with you as you continue on this demanding but deeply rewarding path.