Question 1: Ovarian Dermoid Cyst (Mature Cystic Teratoma)
Stem: A 30-year-old woman undergoes a pelvic CT scan for unrelated appendicitis. An incidental 6 cm right adnexal mass is noted. The mass is well-defined, unilocular, and contains areas of macroscopic fat (measuring -80 Hounsfield Units), as well as several coarse, tooth-like calcifications.
Question: What is the most likely diagnosis?
(A) Ovarian Dermoid Cyst (Mature Cystic Teratoma) (B) Endometrioma (C) Serous Cystadenoma (D) Tubo-ovarian Abscess (E) Pedunculated Leiomyoma
Correct Answer: (A) Ovarian Dermoid Cyst (Mature Cystic Teratoma).
Explanation:
- Why (A) is correct: The presence of macroscopic fat within an adnexal mass is pathognomonic for a dermoid cyst (mature cystic teratoma). These germ cell tumours are composed of mature tissues from all three germ layers, hence they often contain fat (sebum), calcification (teeth), and soft-tissue components (Rokitansky nodule).
- Why (B) is wrong: An endometrioma (“chocolate cyst”) contains chronic blood products, which appear hyperdense on CT and T1-bright on MRI; it does not contain fat.
- Why (C) is wrong: A serous cystadenoma is a simple, thin-walled, fluid-filled cyst and does not contain fat or calcification.
- Why (D) is wrong: A tubo-ovarian abscess is a complex, multiloculated, thick-walled fluid collection associated with clinical signs of infection (fever, pain), not a fat-containing mass.
- Why (E) is wrong: A pedunculated leiomyoma (fibroid) is a solid, soft-tissue mass arising from the uterus, which may calcify but does not contain fat.
Key Points: Ovarian Dermoid Cyst
- Definition: Most common ovarian germ cell tumour; benign.
- Imaging Hallmarks:
- Macroscopic Fat: The key diagnostic feature on CT (<-10 HU) and MRI (signal drop-out on fat-sat).
- Calcification: Often coarse, tooth-like.
- Rokitansky Nodule: A solid, enhancing nodule within the cyst wall from which hair/teeth arise.
- Complications: Ovarian torsion (most common complication), rupture (chemical peritonitis), and rare malignant transformation.
Question 2: Endometrioma
Stem: A 35-year-old woman presents with severe dysmenorrhoea and infertility. A pelvic MRI is performed. It reveals a 4 cm, well-defined cyst in the left ovary. The cyst is uniformly hyperintense (bright) on T1-weighted images and hypointense (dark) on T2-weighted images, with internal, low-signal, “T2-shading” effects.
Question: This specific MRI signal characteristic is most diagnostic of:
(A) Haemorrhagic Cyst (B) Endometrioma (C) Ovarian Dermoid Cyst (D) Simple Cyst (E) Mucinous Cystadenoma
Correct Answer: (B) Endometrioma.
Explanation:
- Why (B) is correct: This is the classic MRI appearance of an endometrioma (“chocolate cyst”). The T1 hyperintensity is due to the high protein and iron content of chronic, repeated haemorrhage. The T2 hypointensity (“shading”) is also due to the high concentration of chronic blood products, which causes T2 shortening.
- Why (A) is wrong: An acute haemorrhagic cyst is also T1-bright, but it is typically T2-bright (like simple fluid) and should resolve on a follow-up scan. T2-shading implies chronic, concentrated blood.
- Why (C) is wrong: A dermoid cyst is diagnosed by fat, which is T1-bright but would lose signal on fat-suppressed T1 sequences (unlike an endometrioma, which stays bright).
- Why (D) is wrong: A simple cyst is T1-dark and T2-bright (simple fluid).
- Why (E) is wrong: A mucinous cystadenoma is typically a large, multi-septated cyst with T1-dark/T2-bright fluid.
Key Points: Endometrioma
- Definition: A cystic collection of ectopic endometrial tissue within the ovary.
- Clinical: Associated with endometriosis, dysmenorrhoea, and infertility.
- MRI Hallmarks:
- T1-hyperintense (bright) – does not suppress with fat-saturation.
- T2-hypointense (dark) or shows “T2 shading.”
- Ultrasound: Often a “ground-glass” appearance (homogeneous, low-level internal echoes).
Question 3: Uterine Leiomyoma (Fibroid)
Stem: A 42-year-old woman presents with heavy menstrual bleeding (menorrhagia). A pelvic ultrasound demonstrates a 5 cm, well-defined, hypoechoic, solid mass with a “whorled” internal texture and peripheral shadowing, located within the myometrium of the uterine fundus.
Question: What is the most likely diagnosis?
(A) Leiomyoma (Fibroid) (B) Adenomyosis (C) Endometrial Polyp (D) Ovarian Mass (E) Endometrial Carcinoma
Correct Answer: (A) Leiomyoma (Fibroid).
Explanation:
- Why (A) is correct: This is the classic ultrasound appearance of a uterine leiomyoma (fibroid). They are benign smooth muscle tumours, typically appearing as well-defined, hypoechoic, solid masses in the myometrium. The “whorled” texture and posterior acoustic shadowing are also characteristic.
- Why (B) is wrong: Adenomyosis is an ill-defined, diffuse process, typically appearing as asymmetric thickening of the myometrium with an indistinct endo-myometrial border, not a discrete, well-defined mass.
- Why (C) is wrong: An endometrial polyp is a focal, echogenic mass within the endometrial cavity, not a hypoechoic mass in the myometrium.
- Why (D) is wrong: The mass is described as being in the myometrium (uterine wall), not the ovary.
- Why (E) is wrong: Endometrial carcinoma is an irregular, thickened, endometrial-based lesion, typically seen in post-menopausal women.
Key Points: Leiomyoma (Fibroid)
- Definition: Extremely common benign smooth muscle tumour of the myometrium.
- Clinical: Often asymptomatic; can cause menorrhagia, pelvic pain, or infertility.
- Ultrasound: Classically a well-defined, hypoechoic, solid mass with a whorled texture and posterior acoustic shadowing.
- Locations: Subserosal (on the outside), Intramural (in the wall), Submucosal (projecting into the cavity).
Question 4: Adenomyosis
Stem: A 45-year-old woman presents with severe dysmenorrhoea and menorrhagia. A pelvic MRI is performed. The T2-weighted images demonstrate diffuse, ill-defined thickening of the junctional zone, which measures 16 mm (normal < 8-12 mm). Multiple small, T2-bright foci are seen within this thickened zone.
Question: What is the most likely diagnosis?
(A) Leiomyoma (B) Adenomyosis (C) Endometrial Carcinoma (D) Normal Uterus (E) Pelvic Congestion Syndrome
Correct Answer: (B) Adenomyosis.
Explanation:
- Why (B) is correct: Diffuse thickening of the junctional zone to > 12 mm on T2-weighted MRI is the most specific sign of adenomyosis (ectopic endometrial glands and stroma within the myometrium). The small, T2-bright foci represent ectopic cystic glands.
- Why (A) is wrong: A leiomyoma is a focal, well-defined mass, not a diffuse thickening of a normal uterine layer.
- Why (C) is wrong: Endometrial carcinoma is a mass within the endometrium that may invade the myometrium, but it doesn’t present as isolated, diffuse junctional zone thickening.
- Why (D) is wrong: A normal junctional zone is a thin, dark line (< 8-12 mm) on T2.
- Why (E) is wrong: Pelvic congestion syndrome involves dilated, tortuous pelvic veins, not uterine wall thickening.
Key Points: Adenomyosis
- Definition: Ectopic endometrial glands and stroma within the myometrium.
- Clinical: Dysmenorrhoea (painful periods), menorrhagia (heavy periods).
- MRI (Best Modality):
- Thickened Junctional Zone (JZ) > 12 mm on T2-weighted images.
- Ill-defined, low-signal border between endometrium and myometrium.
- T2-bright foci (cystic glands/haemorrhage) within the thickened JZ.
Question 5: Ectopic Pregnancy
Stem: A 24-year-old woman presents with 6 weeks of amenorrhoea, right-sided pelvic pain, and a positive serum beta-hCG. A transvaginal ultrasound reveals an empty uterine cavity with a thin endometrial stripe. In the right adnexa, there is a 2 cm, complex, echogenic ring-like structure, separate from the ovary.
Question: This combination of findings is most concerning for:
(A) Ruptured Corpus Luteum Cyst (B) Ectopic Pregnancy **(C) ** Early Intrauterine Pregnancy (not yet visible) (D) Tubo-ovarian Abscess (E) Molar Pregnancy
Correct Answer: (B) Ectopic Pregnancy.
Explanation:
- Why (B) is correct: The clinical triad of positive beta-hCG, an empty uterus, and adnexal pain/mass is highly suspicious for an ectopic pregnancy. The “tubal ring sign” (an echogenic ring surrounding an anechoic sac in the adnexa) is a specific sign.
- Why (A) is wrong: A ruptured corpus luteum cyst would also cause pain and adnexal findings, but it would not produce a “tubal ring” and would be located within the ovary.
- Why (C) is wrong: In a normal pregnancy at 6 weeks with a positive hCG, a gestational sac (and likely yolk sac) should be visible within the uterus on transvaginal US (the “discriminatory zone”).
- Why (D) is wrong: A TOA is an inflammatory mass and is not associated with a positive beta-hCG.
- Why (E) is wrong: A molar pregnancy would show an abnormal, “snowstorm” appearance within the uterus.
Key Points: Ectopic Pregnancy
- Definition: Implantation of a pregnancy outside the uterine cavity (most commonly in the ampulla of the fallopian tube).
- Clinical: Positive beta-hCG + Empty Uterus + Adnexal Mass/Pain.
- Ultrasound Signs:
- “Tubal Ring Sign”: Echogenic ring in the adnexa, separate from the ovary.
- Adnexal mass with a yolk sac or fetal pole.
- Free fluid/haemoperitoneum (if ruptured).
- Note: This is a gynaecological emergency.
Question 6: Tubo-ovarian Abscess (PID)
Stem: A 28-year-old woman presents with a 5-day history of high fever, purulent vaginal discharge, and severe, bilateral lower abdominal pain. A CT scan of the pelvis shows complex, thick-walled, multiloculated, rim-enhancing fluid collections in both adnexae, which appear to involve and obscure the fallopian tubes and ovaries. There is surrounding inflammatory fat stranding.
Question: This appearance is most characteristic of:
(A) Bilateral Endometriomas (B) Bilateral Ovarian Dermoid Cysts (C) Bilateral Tubo-ovarian Abscesses (D) Ovarian Torsion (E) Bilateral Ectopic Pregnancies
Correct Answer: (C) Bilateral Tubo-ovarian Abscesses.
Explanation:
- Why (C) is correct: The clinical context of fever, discharge, and pain (Pelvic Inflammatory Disease – PID) combined with the imaging findings of complex, bilateral, rim-enhancing fluid collections is classic for tubo-ovarian abscesses (TOA).
- Why (A) is wrong: Endometriomas are chronic blood cysts and would not present with high fever or have thick, enhancing, inflammatory rims.
- Why (B) is wrong: Dermoid cysts are fat-containing and not inflammatory.
- Why (D) is wrong: Torsion is typically unilateral and presents as an enlarged, solid, oedematous ovary with absent blood flow.
- Why (E) is wrong: This is extremely rare and would be associated with a positive beta-hCG, not a high fever.
Key Points: Tubo-ovarian Abscess (TOA)
- Definition: A severe complication of Pelvic Inflammatory Disease (PID).
- Clinical: Fever, leukocytosis, pelvic pain, vaginal discharge, cervical motion tenderness.
- Imaging (US/CT):
- Complex, multiloculated, thick-walled, rim-enhancing fluid collection(s).
- Involves and obscures the normal tubo-ovarian structures.
- Associated pelvic fat stranding and inflammation.
Question 7: Septate Uterus
Stem: A 29-year-old woman is being investigated for recurrent first-trimester miscarriages. An MRI of the pelvis is performed, which shows a single uterine cervix and body, but a complete fibrous band dividing the endometrial cavity. The external fundal contour of the uterus is convex (normal).
Question: This combination of a divided cavity and a normal external contour is diagnostic of:
(A) Uterine Didelphys (B) Bicornuate Uterus **(C) ** Septate Uterus (D) Arcuate Uterus (E) Unicornuate Uterus
Correct Answer: (C) Septate Uterus.
Explanation:
- Why (C) is correct: The key differentiator for Mullerian duct anomalies is the external fundal contour. A septate uterus is a fusion anomaly (failure of the dividing septum to resorb), so the external contour is normal (convex or flat). This type is most associated with recurrent miscarriage.
- Why (A) is wrong: Uterine didelphys (complete non-fusion) results in two separate uterine horns and two cervices.
- Why (B) is wrong: A bicornuate uterus (partial non-fusion) has a deep external fundal cleft (> 1 cm), splitting the uterine horns.
- Why (D) is wrong: An arcuate uterus is a minor variant with only a mild, broad indentation of the inner cavity and a normal outer contour.
- Why (E) is wrong: A unicornuate uterus is the failure of one Mullerian duct to develop, resulting in a small, “banana-shaped” uterus.
Key Points: Septate vs. Bicornuate Uterus
- Both have a divided endometrial cavity (two “horns”).
- Septate: Failure of resorption. Normal (Convex) external fundal contour. (Worst obstetric outcome).
- Bicornuate: Failure of fusion. Deeply Cleft (> 1 cm) external fundal contour.
Question 8: Hysterosalpingogram (HSG)
Stem: A 34-year-old woman is undergoing an infertility workup. A hysterosalpingogram (HSG) is performed. The images demonstrate a normal uterine cavity and normal opacification of both fallopian tubes. Crucially, contrast is seen spilling freely from the fimbriated ends of both tubes into the peritoneal cavity.
Question: What is the correct interpretation of this finding?
(A) Bilateral tubal occlusion. (B) Bilateral hydrosalpinx. **(C) ** Bilateral patent (open) fallopian tubes. (D) Uterine septum. (E) Asherman’s Syndrome.
Correct Answer: (C) Bilateral patent (open) fallopian tubes.
Explanation:
- Why (C) is correct: The entire purpose of an HSG is to assess uterine morphology and tubal patency. “Spill” of contrast into the peritoneal cavity is the desired, normal finding, as it confirms that the tubes are patent (open).
- Why (A) is wrong: Bilateral occlusion would be diagnosed by a lack of contrast spill.
- Why (B) is wrong: A hydrosalpinx (a blocked, fluid-filled tube) would appear as a dilated, club-shaped fallopian tube with no spill.
- Why (D) is wrong: A uterine septum is a filling defect within the uterus.
- Why (E) is wrong: Asherman’s syndrome (intrauterine adhesions) would present as irregular filling defects within the uterine cavity.
Key Points: Hysterosalpingogram (HSG)
- Purpose: Assesses uterine cavity and tubal patency in infertility.
- Key Finding: “Spill” of contrast from the fimbriated ends.
- Spill = Patent (Normal).
- No Spill = Occlusion (Abnormal).
- Dilated Tube + No Spill = Hydrosalpinx.
Question 9: Ovarian Serous Cystadenocarcinoma
Stem: A 68-year-old post-menopausal woman presents with new-onset abdominal bloating and a raised CA-125 level. A CT scan reveals large, bilateral, multiloculated cystic ovarian masses. The key finding is the presence of multiple solid, enhancing mural nodules and thick, enhancing septations within the cysts.
Question: The presence of solid, enhancing nodules is the most specific sign for:
(A) Malignancy (e.g., Cystadenocarcinoma) (B) Endometrioma (C) Simple Cyst (D) Dermoid Cyst (E) Tubo-ovarian Abscess
Correct Answer: (A) Malignancy (e.g., Cystadenocarcinoma).
Explanation:
- Why (A) is correct: In a complex ovarian cyst, the most reliable imaging feature of malignancy is the presence of a solid, enhancing mural nodule (papillary projection) or thick, enhancing septations (> 3 mm). This, combined with the patient’s age and high CA-125, is classic for an ovarian epithelial malignancy like serous cystadenocarcinoma.
- Why (B) is wrong: An endometrioma is a benign cyst with a “ground-glass” appearance; it does not have enhancing solid nodules.
- Why (C) is wrong: A simple cyst is thin-walled, unilocular, and has no solid components.
- Why (D) is wrong: A dermoid cyst contains fat and calcification (Rokitansky nodule), but not typically papillary, enhancing nodules.
- Why (E) is wrong: A TOA is an inflammatory mass with a thick, shaggy, enhancing rim, but it is filled with pus/debris, not true solid nodules.
Key Points: Ovarian Cancer (Epithelial)
- Demographic: Typically post-menopausal women.
- Tumour Marker: CA-125 (often elevated).
- Malignant Imaging Features (US/CT/MRI):
- Solid, enhancing components (mural nodules/papillary projections).
- Thick, irregular, enhancing septations (> 3 mm).
- Large size, bilateral, associated ascites/peritoneal mets (“omental cake”).
Question 10: Placenta Previa
Stem: A 32-year-old woman at 30 weeks gestation (G1P0) presents to the hospital with a 1-hour history of painless, bright red vaginal bleeding. A transabdominal ultrasound is performed, which confirms the placental tissue is completely covering the internal cervical os.
Question: What is the most likely diagnosis?
(A) Placenta Previa (B) Placental Abruption (C) Vasa Previa (D) Placenta Accreta (E) Uterine Rupture
Correct Answer: (A) Placenta Previa.
Explanation:
- Why (A) is correct: This is the definition of placenta previa (or praevia). The painless nature of the bleeding is the key clinical differentiator. The ultrasound confirms the diagnosis by showing the placenta covering the internal os.
- Why (B) is wrong: Placental abruption (separation of the placenta) is a medical emergency that classically presents with PAINFUL vaginal bleeding and uterine tenderness.
- Why (C) is wrong: Vasa previa is when fetal vessels (not the placenta itself) run over the internal os. Rupture is catastrophic for the fetus.
- Why (D) is wrong: Placenta accreta is abnormal invasion of the placenta into the uterine wall, not its location over the os (though the two are strongly associated).
- Why (E) is wrong: Uterine rupture is a catastrophic event, usually in a scarred uterus, presenting with acute, severe pain.
Key Points: Placenta Previa
- Definition: The placenta partially or completely covers the internal cervical os.
- Clinical: Painless, bright red vaginal bleeding in the 2nd or 3rd trimester.
- Diagnosis: Ultrasound (transvaginal is the gold standard for accurate measurement).
- Management: Requires C-section delivery.
Question 11: Placenta Accreta
Stem: A 38-year-old woman (G4P3), with a history of three prior Caesarean sections, undergoes a screening antenatal MRI. The placenta is noted to be anterior and low-lying. The key finding on T2-weighted images is a focal loss of the normal T2-hypointense retroplacental stripe (myometrium) and several large, T2-dark bands within the placenta.
Question: These MRI findings are most concerning for:
(A) Placenta Accreta Spectrum (B) Placental Abruption (C) Normal Placenta (D) Molar Pregnancy (E) Chorioangioma
Correct Answer: (A) Placenta Accreta Spectrum.
Explanation:
- Why (A) is correct: Placenta accreta (increta, percreta) is the abnormal invasion of the placenta into the uterine wall. The biggest risk factor is prior C-section (uterine scarring). The key MRI finding is the loss of the T2-dark retroplacental line (the myometrium), which indicates it has been invaded by the placenta. The dark T2 bands are also a sign of placental fibrosis.
- Why (B) is wrong: An abruption would appear as a retroplacental haematoma (blood collection), not an invasion.
- Why (C) is wrong: A normal placenta would have a clear, intact T2-dark myometrial stripe.
- Why (D) is wrong: A molar pregnancy is a cystic, “bunch of grapes” mass.
- Why (E) is wrong: A chorioangioma is a benign, focal vascular tumour within the placenta.
Key Points: Placenta Accreta Spectrum
- Definition: Abnormal placental invasion into the myometrium.
- Risk Factors: Prior C-section, placenta previa, advanced maternal age.
- MRI Signs:
- Loss of the T2-hypointense retroplacental stripe (myometrium).
- T2-dark intraplacental bands.
- Bulging of the uterus, invasion into the bladder.
- Complication: Life-threatening post-partum haemorrhage.
Question 12: Molar Pregnancy (GTD)
Stem: A 22-year-old woman presents at 12 weeks gestation with severe hyperemesis and vaginal bleeding. Her serum beta-hCG level is > 400,000 IU/L. A pelvic ultrasound reveals an enlarged uterus filled with a diffuse, echogenic, microcystic mass, described as a “snowstorm” appearance. No fetal parts are identified. Both ovaries are enlarged and contain multiple, large, septated cysts.
Question: This combination of findings is diagnostic of:
(A) Complete Molar Pregnancy (B) Partial Molar Pregnancy (C) Missed Miscarriage (D) Ectopic Pregnancy (E) Normal Twin Pregnancy
Correct Answer: (A) Complete Molar Pregnancy.
Explanation:
- Why (A) is correct: This is the classic presentation of a complete mole (a form of Gestational Trophoblastic Disease – GTD). The key features are: 1) Very high beta-hCG, 2) “Snowstorm” or “bunch of grapes” appearance of the uterus on US, 3) Absence of fetal parts, and 4) Bilateral, large theca lutein cysts (from ovarian hyperstimulation by the high hCG).
- Why (B) is wrong: A partial mole is triploid, and would typically show both molar tissue and identifiable (but abnormal) fetal parts.
- Why (C) is wrong: A missed miscarriage would show a non-viable fetus or empty sac, not a “snowstorm” mass.
- Why (D) is wrong: An ectopic pregnancy is outside the uterus.
- Why (E) is wrong: A normal twin pregnancy would show two distinct gestational sacs.
Key Points: Complete Molar Pregnancy
- Definition: A form of GTD; diploid, entirely paternal in origin.
- Clinical: Markedly elevated beta-hCG, hyperemesis, pre-eclampsia.
- Ultrasound:
- “Snowstorm” or “bunch of grapes” uterus.
- No fetal parts.
- Bilateral theca lutein cysts in the ovaries.
- Risk: Can progress to invasive mole or choriocarcinoma.
Question 13: Ovarian Torsion
Stem: A 19-year-old woman presents with the sudden, severe onset of right lower quadrant pain and vomiting. A pelvic ultrasound reveals a markedly enlarged, oedematous right ovary (8 cm) with peripherally displaced follicles. Colour Doppler shows absent arterial and venous flow to this ovary.
Question: What is the most likely diagnosis?
(A) Haemorrhagic Ovarian Cyst (B) Tubo-ovarian Abscess (C) Ectopic Pregnancy (D) Ovarian Torsion (E) Appendicitis
Correct Answer: (D) Ovarian Torsion.
Explanation:
- Why (D) is correct: The acute onset of severe pain, a unilaterally enlarged oedematous ovary, and absent Doppler flow are the classic findings of ovarian torsion. The twisting of the adnexal pedicle cuts off venous outflow first (causing oedema and enlargement), followed by arterial inflow (causing infarction and absent flow).
- Why (A) is wrong: A haemorrhagic cyst would be painful but would not cause the entire ovary to lose its blood supply.
- Why (B) is wrong: A TOA is an inflammatory mass with increased blood flow (hyperaemia) and signs of infection.
- Why (C) is wrong: An ectopic pregnancy would have a positive beta-hCG and a specific adnexal mass.
- Why (E) is wrong: Appendicitis would show an inflamed appendix; the ovary would be normal.
Key Points: Ovarian Torsion
- Definition: Twisting of the ovarian vascular pedicle, leading to ischaemia. A surgical emergency.
- Risk: Often due to an underlying mass (e.g., dermoid, large cyst) that acts as a pivot point.
- Ultrasound (Key Signs):
- Unilaterally enlarged, oedematous ovary.
- Absent (or high-resistance) arterial and venous flow on Doppler.
- “Follicular ring sign” (peripherally displaced follicles).
- “Whirlpool sign” (twisted pedicle).
Question 14: Endometrial Carcinoma
Stem: A 72-year-old woman presents with post-menopausal bleeding. A transvaginal ultrasound reveals an irregularly thickened endometrium measuring 20 mm. An MRI is performed for staging.
Question: On the T2-weighted MRI images, what is the most important finding for determining a T-stage of T1b versus T1a?
(A) The overall size of the tumour. (B) The presence of pelvic lymph nodes. (C) The depth of tumour invasion into the myometrium. (D) Invasion of the cervical stroma. (E) Invasion of the parametrium.
Correct Answer: (C) The depth of tumour invasion into the myometrium.
Explanation:
- Why (C) is correct: For endometrial cancer, Stage I is confined to the uterine body. The key substage distinction, which guides therapy (e.g., need for adjuvant radiation), is the depth of myometrial invasion:
- Stage T1a: Tumour invades < 50% of the myometrial thickness.
- Stage T1b: Tumour invades > 50% of the myometrial thickness.
- Why (A) is wrong: Tumour size is not the primary T-stage determinant.
- Why (B) is wrong: Lymph nodes are the “N” stage, not the “T” stage.
- Why (D) is wrong: Invasion of the cervical stroma makes it Stage T2.
- Why (E) is wrong: This is not a primary staging criterion for endometrial cancer (it is for cervical).
Key Points: Endometrial Carcinoma
- Most common gynaecological malignancy.
- Clinical: Post-menopausal bleeding (PMB).
- Ultrasound: Thickened endometrium (abnormal if > 4-5 mm in a post-menopausal patient).
- MRI (Staging): Best modality.
- Tumour is T2-intermediate/bright, endometrium is bright.
- Key finding is invasion through the T2-dark junctional zone into the myometrium.
- T1a = < 50% myometrial invasion.
- T1b = > 50% myometrial invasion.
Question 15: Cervical Carcinoma
Stem: A 45-year-old woman with post-coital bleeding is diagnosed with invasive cervical carcinoma. A pelvic MRI is performed for staging. The T2-weighted images show a 3 cm tumour confined to the cervix. However, there is clear extension of the T2-intermediate tumour signal beyond the T2-dark cervical stroma, invading the left parametrium.
Question: According to the FIGO staging system, this finding of parametrial invasion classifies the tumour as at least:
(A) Stage IB (B) Stage IIA (C) Stage IIB (D) Stage IIIA (E) Stage IIIB
Correct Answer: (C) Stage IIB.
Explanation:
- Why (C) is correct: This is the most critical staging distinction made by MRI. The parametrium is the T2-dark fibrous tissue/ligaments lateral to the cervix.
- Stage I = Tumour confined to the cervix.
- Stage IIA = Tumour invades the upper 2/3 of the vagina, without parametrial invasion.
- Stage IIB = Tumour invades the parametrium.
- Why (A) is wrong: Stage IB is confined to the cervix.
- Why (B) is wrong: Stage IIA involves the vagina, not the parametrium.
- Why (D) & (E) are wrong: Stage III involves the lower 1/3 of the vagina or the pelvic side wall / causes hydronephrosis.
Key Points: Cervical Carcinoma
- Definition: Malignancy arising from the cervix (usually squamous cell from HPV).
- Staging Modality: MRI is the gold standard for T-staging.
- Key Staging Question: Is there parametrial invasion?
- T2-dark cervical stroma should be intact.
- Stage I: Confined to cervix.
- Stage IIA: Invades vagina (upper 2/3).
- Stage IIB: Invades parametrium. (This finding makes the tumour non-surgical, treated with chemoradiation)
