PA29.2-10 | Female Genital Tract — Glossary

Presence of endometrial glands and stroma within the myometrium at a depth >2.5 mm below the endomyometrial junction; thought to arise by direct downgrowth of the basal endometrium.

Oncofetal protein normally produced by the yolk sac and fetal liver; the primary tumor marker for yolk sac tumor (endodermal sinus tumor); also elevated in hepatocellular carcinoma and immature teratoma

Describing a genome in which all chromosomes are derived from paternal (sperm) origin, with no maternal contribution; characteristic of complete hydatidiform mole.

The enzyme (CYP19A1) that converts androgens to estrogens; expressed in adipose tissue, causing obese women to have elevated peripheral estrogen production independent of ovarian function.

Endometrial hyperplasia characterised by nuclear atypia (prominent nucleoli, loss of polarity, vesicular chromatin); direct precursor to endometrioid carcinoma.

The permanent, deepest layer of the endometrium; not shed during menstruation; the source of endometrial regeneration; the layer whose glands invaginate to cause adenomyosis.

Ovarian epithelial tumor with epithelial proliferation and atypia exceeding that of a benign tumor but without stromal invasion; also called 'low malignant potential' (LMP) tumor; can spread to peritoneum but generally has excellent prognosis

Homologous recombination deficiency (HRD) phenotype present in tumors with BRCA1/2 mutations or other HRD-causing alterations; associated with sensitivity to platinum chemotherapy and PARP inhibitors

Cancer antigen 125; a glycoprotein shed by Müllerian epithelium; elevated in >80% of high-grade serous carcinomas; also elevated in benign conditions (endometriosis, PID, liver disease); used for monitoring treatment response, not primary screening

Small follicle-like structures containing central pink amorphous material within granulosa cell tumor; considered pathognomonic; represents abortive follicle formation

Acute haemorrhagic infarction of a leiomyoma, typically occurring during pregnancy; presents with sudden severe pelvic pain and a tender uterus.

Recurring right-sided pneumothorax coinciding with menstruation, caused by diaphragmatic or pleural endometrial implants that bleed and perforate the diaphragm cyclically.

Immunohistochemical marker (CALLA/neprilysin) strongly expressed by endometrial stromal cells; used to confirm endometrial stroma in histologically ambiguous endometriosis, adenomyosis, or endometrial stromal tumours.

Inflammation of the cervix, categorized as acute (neutrophilic) or chronic (lymphoplasmacytic), caused by infectious or non-infectious stimuli.

An ovarian endometrioma filled with dark brown, inspissated, altered blood from recurrent cyclical haemorrhage of ectopic endometrial tissue.

Endometriosis within the ovary forming a cyst filled with dark viscous old blood resembling melted chocolate; the most common macroscopic form of ovarian endometriosis.

A highly malignant trophoblastic tumor composed of biphasic sheets of cytotrophoblast and syncytiotrophoblast without chorionic villi; chemosensitive.

A central fluid-filled space within a hydropic villus, formed by stromal oedema; characteristically seen in complete hydatidiform mole.

A specific type of necrosis in smooth muscle tumors where ghost outlines of tumor cells are preserved; one of the three Stanford criteria for leiomyosarcoma.

Theory proposing that totipotent coelomic peritoneal cells undergo metaplastic transformation to endometrial-type epithelium; explains endometriosis in males and in anatomically inaccessible sites.

Nucleus with a longitudinal groove giving the appearance of a coffee bean; characteristic of granulosa cell tumors and Brenner tumors; distinct from the longitudinal nuclear groove of papillary thyroid carcinoma

A histological growth pattern in which tumour glands form a sieve-like ('cribriform') arrangement with gland-within-gland formation and no intervening stroma; characteristic of confluent endometrioid carcinoma.

The mononuclear, inner layer of trophoblast cells with clear cytoplasm and a distinct cell border; proliferative compartment of trophoblast.

An intermediate filament protein expressed in muscle cells; positive immunostaining for desmin (along with SMA and h-caldesmon) confirms smooth muscle differentiation in uterine tumours.

Reactive fibroblastic stromal response associated with invasive carcinoma; a key low-power indicator of stromal invasion in endometrial carcinoma.

Most common malignant germ cell tumor of the ovary; counterpart of testicular seminoma; uniform cells with clear cytoplasm in sheets separated by lymphocyte-rich fibrous septae; highly radiosensitive and chemosensitive

Pain experienced during sexual intercourse; in the context of endometriosis, typically deep dyspareunia caused by fibrosis and adhesions in the posterior cul-de-sac and uterosacral ligaments.

Physiological eversion of the columnar endocervical epithelium onto the ectocervix, most marked during puberty and pregnancy; the exposed columnar cells are prone to metaplasia and infection.

Abnormal proliferation of endometrial glands with increased gland-to-stroma ratio; classified as simple or complex, with or without atypia.

WHO 2014/2020 term for atypical endometrial hyperplasia — a premalignant lesion with cytological atypia and crowded back-to-back glands, carrying a 25-40% risk of progression to endometrioid carcinoma.

The most common histological subtype of endometrial carcinoma (Type I), showing glandular architecture resembling normal proliferative endometrium; associated with estrogen excess and PTEN loss.

Presence of functional endometrial glands and stroma outside the uterine cavity; estrogen-dependent; the leading surgically confirmed cause of chronic pelvic pain and infertility in women of reproductive age.

Clear cell and endometrioid carcinomas that arise directly within ovarian endometriosis (chocolate cysts); ARID1A and PIK3CA mutations are molecular drivers; collectively account for ~20% of ovarian carcinomas

The histological boundary between the endometrium (basalis layer) and the myometrium; disruption of this interface is implicated in the pathogenesis of adenomyosis.

International Federation of Gynecology and Obstetrics surgical staging system for endometrial carcinoma, based on depth of myometrial invasion, cervical and adnexal involvement, and distant spread.

A histological pattern of chronic cervicitis characterized by reactive lymphoid follicles with germinal centers in the cervical stroma; strongly associated with Chlamydia trachomatis infection.

C134W point mutation in the FOXL2 transcription factor; present in >95% of adult-type granulosa cell tumors; a highly specific molecular diagnostic marker distinguishing this tumor from other sex cord–stromal neoplasms

Severe endometriosis with dense fibrous adhesions obliterating the pouch of Douglas and binding the uterus, tubes, ovaries, and bowel together; produces fixed retroversion and severe dyspareunia.

Coagulative necrosis within a smooth muscle tumour showing abrupt transition between viable and necrotic tumour cells; one of the three Stanford criteria distinguishing leiomyosarcoma from leiomyoma.

Gonadotropin-releasing hormone analogue (e.g., leuprolide, goserelin) that down-regulates pituitary GnRH receptors, suppressing ovarian estrogen production; a medical treatment for estrogen-dependent conditions including endometriosis and adenomyosis.

Most important malignant sex cord–stromal tumor; produces estrogen; adult type shows Call-Exner bodies, coffee-bean nuclear grooves, and FOXL2 mutation; characterized by late recurrence ('Sleeping Beauty' tumor)

Macrophages containing golden-brown iron-storage pigment (hemosiderin), derived from the breakdown of red blood cells after haemorrhage; one of the three histological components of the endometriosis diagnostic triad.

The most lethal ovarian malignancy; bilateral, papillary with marked nuclear atypia, psammoma bodies, TP53 mutation; presents at advanced stage.

A tumor cell whose nucleus protrudes into the glandular lumen while the cytoplasm is scant, resembling a hobnail boot tack; characteristic of clear cell carcinoma of the ovary

Tumour cells with nuclei that protrude apically into the gland lumen, resembling the nail of a hobnail boot; seen in serous and clear cell carcinomas of the female genital tract.

A polypeptide hormone produced predominantly by intermediate trophoblast and syncytiotrophoblast; the principal marker for PSTT.

An abnormal pregnancy characterised by trophoblastic proliferation and hydropic swelling of chorionic villi, classified as complete or partial based on karyotype and histology.

Chorionic villi showing stromal oedema with accumulation of fluid, leading to cystic cistern formation; a hallmark of gestational trophoblastic disease.

Malignant germ cell tumor containing immature (embryonic) tissue, especially primitive neuroepithelium; graded I–III by proportion of immature neural elements per slide; treated with BEP chemotherapy

Gonadal glycoprotein hormone that suppresses FSH; secreted by granulosa cells and theca cells; used as a serum tumor marker for granulosa cell tumors and thecomas

A hydatidiform mole in which hydropic villi penetrate directly into the myometrium or enter uterine vasculature; villi retain their identity, unlike choriocarcinoma.

On MRI, the innermost layer of the myometrium corresponding to the basalis and inner myometrium; thickening >12 mm is diagnostic of adenomyosis on imaging.

Bilateral metastatic signet-ring cell carcinoma of the ovary, usually from gastric adenocarcinoma; characterized by mucin-filled signet-ring cells in a cellular fibromatous ovarian stroma

Benign smooth muscle tumour of the myometrium ('fibroid'); presents as a firm, well-circumscribed nodule with a whorled cut surface and fibrous pseudocapsule; distinguished from adenomyosis by capsule, texture, and histology.

A malignant smooth muscle tumour of the uterus, arising de novo, characterised histologically by severe atypia, ≥ 10 mitoses per 10 HPF, and tumour cell necrosis (Stanford criteria).

Autosomal dominant hereditary cancer syndrome caused by germline mismatch repair gene mutations (MLH1, MSH2, MSH6, PMS2), causing increased risk of colorectal, endometrial, ovarian, and other cancers.

A benign germ-cell tumor containing well-differentiated elements from all three germ layers; ectoderm predominates — squamous epithelium, hair follicles, sebaceous glands, teeth.

Mediator complex subunit 12 — a transcriptional regulator gene; mutations in MED12 are found in ~70% of uterine leiomyomas, making it the most frequently mutated gene in these benign tumours.

Clinical triad of benign ovarian fibroma + ascites + right-sided pleural effusion; all features resolve completely after surgical removal of the fibroma

Abnormally heavy or prolonged menstrual bleeding (>80 mL per cycle or lasting >7 days); a hallmark symptom of adenomyosis and submucosal leiomyoma.

Genomic instability caused by defective DNA mismatch repair proteins (MLH1, MSH2, MSH6, PMS2); present in 20-30% of endometrioid carcinomas and hallmark of Lynch syndrome-related cases.

Penetration of endometrial carcinoma into the muscular wall of the uterus; depth (< ½ = Stage IA, ≥ ½ = Stage IB) is the most important intra-uterine prognostic factor.

Mucus retention cyst formed when squamous metaplasia occludes an endocervical gland opening; appears as a yellowish dome on the ectocervix; a normal finding in parous women.

Solid replacement of the greater omentum by metastatic tumor deposits from ovarian carcinoma; the omentum becomes a firm, irregular solid mass instead of the normal fatty apron

Removal of the fallopian tubes at the time of other pelvic surgery (hysterectomy, tubal ligation) to reduce the risk of high-grade serous carcinoma, based on evidence that STIC lesions in the fimbriae are precursors of most HGSC

A paternally imprinted, maternally expressed cell cycle inhibitor; absent in complete hydatidiform mole (androgenetic) and positive in partial mole and hydropic abortion — used for differential diagnosis.

Class of targeted therapy (e.g., olaparib, niraparib) that blocks base excision repair, causing synthetic lethality in BRCA-mutated/HRD-deficient tumor cells; used as maintenance therapy in HGSC

Histochemical stain that turns hemosiderin (ferric iron) bright blue, confirming the presence of iron-laden macrophages in histological sections; useful in confirming prior haemorrhage in endometriosis or 'burnt-out' lesions.

An outpatient endometrial sampling technique using a thin suction catheter inserted through the cervix; sensitivity ~90% for endometrial carcinoma, avoiding the need for general anaesthesia in most cases.

A rare gestational trophoblastic neoplasm arising from intermediate trophoblast at the implantation site; produces hPL more than hCG; less chemosensitive.

Any vaginal bleeding occurring more than 12 months after the last menstrual period; requires mandatory investigation to exclude endometrial carcinoma.

Dark brown or black punctate peritoneal implants of endometriosis seen at laparoscopy, colored by hemosiderin from repeated cyclic bleeding; also called gunshot lesions.

Concentrically laminated calcified spherule formed by calcification at the tips of papillary fronds following ischemic necrosis; characteristic of high-grade serous carcinoma (and papillary thyroid carcinoma, meningioma)

Accumulation of gelatinous mucin throughout the peritoneal cavity ('jelly belly'); most commonly originates from a low-grade mucinous neoplasm of the appendix; the ovary is usually secondarily involved

Phosphatase and tensin homolog — a tumour suppressor gene that antagonises the PI3K/AKT proliferation pathway; lost in > 80% of atypical hyperplasia and Type I endometrial carcinoma.

Backflow of menstrual debris through the fallopian tubes into the peritoneal cavity, carrying viable endometrial cells that may implant and proliferate as endometriosis; the most widely accepted theory of endometriosis origin.

Solid nodule projecting into the lumen of a mature cystic teratoma (dermoid cyst) from which the diverse tissue elements arise; appears as a hyperechoic nodule with acoustic shadowing on ultrasound

Glomeruloid vascular structure with a central vessel surrounded by a perivascular collar of tumor cells, embedded in a loose myxoid stroma; pathognomonic of yolk sac tumor (endodermal sinus tumor)

Cyclical pelvic pain during menstruation attributable to a structural pelvic pathology (e.g., endometriosis, adenomyosis, fibroids), as opposed to primary dysmenorrhea where no structural cause is found.

An aggressive Type II endometrial carcinoma arising in an atrophic background, driven by TP53 mutation, showing complex papillary architecture with severe nuclear pleomorphism, and prone to early peritoneal spread.

Non-invasive precursor of serous endometrial carcinoma, arising on the surface epithelium or glands of an atrophic endometrium; driven by TP53 mutation.

Rare sex cord–stromal tumor recapitulating testicular architecture; produces androgens causing virilization; characterized by Sertoli cell tubules and interstitial Leydig cells with Reinke crystals in well-differentiated forms

Mucin-filled cell in which the cytoplasmic mucin displaces the nucleus to the cell periphery, creating a crescent-shaped nucleus resembling a signet ring; hallmark of diffuse-type gastric carcinoma and Krukenberg tumor

A uterine smooth muscle tumour that does not meet full criteria for leiomyosarcoma but shows atypical features; requires long-term follow-up due to uncertain behaviour.

The histological boundary between stratified squamous and columnar (glandular) epithelium on the cervix; its position shifts throughout reproductive life.

The three histological criteria for diagnosing leiomyosarcoma: (1) severe cytological atypia, (2) ≥ 10 mitoses per 10 high-power fields, and (3) geographic tumour cell necrosis.

Intraepithelial high-grade serous carcinoma found in the fimbriated end of the fallopian tube; considered the precursor lesion for most high-grade serous ovarian carcinomas

Monodermal teratoma of the ovary composed predominantly of thyroid tissue; may cause hyperthyroidism; takes up radioiodine on nuclear scan

The multinucleate outer trophoblastic layer with abundant eosinophilic cytoplasm and irregular nuclei; produces hCG and hPL.

Spread of malignant cells through the peritoneal cavity via peritoneal fluid; the dominant route of spread for ovarian carcinoma; leads to omental caking, peritoneal deposits, and ascites

The area on the ectocervix where columnar endocervical epithelium transitions to squamous epithelium via squamous metaplasia; the site of origin for CIN and cervical carcinoma.

First-line imaging investigation for postmenopausal bleeding; endometrial thickness ≥ 4 mm in a postmenopausal woman warrants endometrial biopsy.

Containing three complete sets of chromosomes (69 chromosomes in humans); the karyotypic basis of partial hydatidiform mole, resulting from dispermic fertilisation of a normal ovum.

Abnormal proliferation of both cytotrophoblast and syncytiotrophoblast around chorionic villi; circumferential in complete mole, focal in partial mole.

Estrogenic stimulation of the endometrium in the absence of physiological or therapeutic progesterone opposition; the primary driver of endometrial hyperplasia and Type I carcinoma.