Ovary and fallopian tube

Question 1

Fallopian tube/ovary containing decidualised endometrial stroma with no glands

Answer 1

Deciduosis (ectopic decidual reaction) of fallopian tube/ovary

Differential diagnosis:
Decidualisation of endometriosis

Plan:
Correlate with clinical history and radiology (?known pregnancy)
Examine further sections / levels (for endometrial type glands to indicate endometriosis)
If patient is known to be pregnant, no specific action required

Question 2

Immature chorionic villi within fallopian tube

Answer 2

Fallopian tube ectopic pregnancy

Plan:
Correlate with clinical history and radiology (?raised bHCG ?USS findings)

Question 3

Ovarian cyst with hierarchical branching of papillary fronds lined by a thin layer of crowded cells with mild to moderate atypia, with epithelial tufting and detachment. May be psammoma bodies.

Answer 3

Ovarian serous borderline tumour

Differential diagnosis:
Seromucinous borderline tumour (if mixture of cell types)

Plan:
Correlate with clinical history and radiology
Examine further sections (e.g. for foci of invasion)
IPX to support Dx: ER, PR, PAX8, WT1 (WT1 would be negative in seromucinous borderline tumour)
Next steps: Synoptic report

Question 4

Ovarian cyst lined by mucinous cells with pseudostratified nuclei (resembling a gastrointestinal mucosa with low grade dysplasia), with tufting and and villous formation, but without stromal invasion

Answer 4

Ovarian borderline mucinous tumour

Differential diagnosis:
LAMN
Other metastasis (e.g. pancreatobiliary)

Plan:
Correlate with clinical history and radiology
Examine further blocks (extensively sample, to identify any areas of intraepithelial carcinoma or invasion)
IPX to support Dx: CK7, PAX8
IPX to discount DDx: CK20, SATB2
Next steps: Synoptic report

Question 5

Ovarian tumour with marked nuclear atypia, necrosis, frequent mitoses. Can be solid mass of eosinophilic cells with slit like spaces (fused papillae), glandular, or SET appearance (anastomosing trabeculae resembling urothelial carcinoma).

Answer 5

Ovarian high grade serous carcinoma

Differential diagnosis:
Embryonal carcinoma
Ovarian endometrioid adenocarcinoma
Metastatic uterine serous carcinoma
Metastatic malignancy to ovary (e.g. melanoma, poorly differentiated carcinoma)
Ovarian mesothelioma

Plan:
Correlate with clinical history and radiology
IPX to support Dx: ER and PR, PAX8, WT1, p16, p53 (expect positive, uterine would be WT1 negative, while endometrioid adenocarcinoma would be p16/p53 wild type)
IPX to discount DDx: SALL4, CD30, S100 SOX10 MelanA, CK20, calretinin, D2-40
Next steps: Synoptic report, discuss at MDT
Advice to clinician: May be associated with BRCA mutation. Clinical correlation is required.

Question 6

An ovarian tumour composed exclusively or predominantly of benign thyroid parenchyma.

Answer 6

Struma ovarii

Plan:
Correlate with clinical history and radiology
Examine further sections (extensively sample, ideally entire lesion, to identify any component of thyroid carcinoma)
IPX: Not required for diagnosis

Question 7

Ovarian lesion with back to back endometrial type glands with high gland to stroma ratio and architectural complexity (may be fused, cribriform, solid). Areas of squamous metaplasia can be seen.

Answer 7

Ovarian endometrioid adenocarcinoma

Differential diagnosis:
Ovarian high grade serous carcinoma
Metastatic endometrial endometrioid adenocarcinoma
Metastatic colon carcinoma

Plan:
Correlate with clinical history and radiology (?history of endometriosis / endometriotic cyst ?uterine lesion ?colon lesion)
Examine further blocks (e.g. for FIGO grade)
IPX to support Dx: ER and PR, CK7, PAX8. Also needs MMR
IPX to discount DDx: p53 and p16, CK20 and SATB2
Next steps: Synoptic report, discuss at MDT

Question 8

Ovarian tumour with nodular mass of cells with abundant clear cytoplasm, well defined membranes, and large, angular nuclei with coarse chromatin and prominent nucleoli. Packets of cells are separated by delicate branching fibrovascular septa. There is lymphocytic inflammation and often granulomatous inflammation, and there can be areas of fibrosis.

Answer 8

Dysgerminoma

Differential diagnosis:
Other germ cell tumours (embryonal carcinoma or yolk sac tumour)
Ovarian clear cell carcinoma
Lymphoma

Plan:
Correlate with clinical history and radiology (?raised LDH)
Examine further sections (extensively sample lesion, to identify any other germ cell tumour components)
IPX to support Dx: SALL4, CD117, PLAP, OCT3/4
IPX to discount DDx: CD30, AFP, glypican 3, Napsin A and HNF1b, CD45 and CD20
Next steps: Synoptic report, discuss at MDT

Question 9

Closely packed cells with pale blue, folded or angulated “coffee bean” nuclei (with longitudinal groove). Cells arrange in cords and rows creating “watered silk” architecture like a topographic map. May form Call-Exner bodies, a rosette of granulosa cells surrounding a pink globule

Answer 9

Adult type granulosa cell tumour

Differential diagnosis:
Cellular thecoma / fibrothecoma

Plan:
Correlate with clinical history and radiology (?hormone production)
Examine further blocks (e.g. for total size, areas of differing morphology)
Special stain to discount DDx: Reticulin (would highlight pericellular fibres in fibroma/thecoma)
IPX to support Dx: Inhibin, calretinin, FOXL2
Molecular: Not required for diagnosis. Does have FOXL2 mutation
Next steps: Synoptic report, discuss at MDT

Question 10

Ovarian tumour with nests of urothelial-type epithelium within a fibrotic stroma. Nests may form a lumen with secretions.

Answer 10

Benign Brenner tumour of ovary

Plan:
Correlate with clinical history and radiology
Examine further sections (e.g. for total size, concurrent mucinous cystadenoma, any areas of borderline/malignant features)
IPX: Not required for diagnosis

Question 11

A microcystic ovarian tumour with cords of cells enclosing microcysts, with hyaline globules (both intra and extracytoplasmic) and ‘Schiller-Duval bodies’ which refer to a fibrovascular core with a distinct central vessel, lined by cuboidal to columnar tumour cells, and surrounded by a cystic space.

Answer 11

Yolk sac tumour

Differential diagnosis:
Ovarian clear cell carcinoma

Plan:
Correlate with clinical history and radiology (?raised AFP)
Examine further sections (extensively sample, ideally entire tumour, to identify other germ cell tumour components)
IPX to support Dx: SALL4, AFP, glypican 3
IPX to discount DDx: Napsin A, HNF1b
Next steps: Synoptic report, discuss at MDT