Ovarian Tumor Grading
Endometrioid, mucinous, immature teratoma, and Sertoli-Leydig cell tumor grading modules in one app.
Free with an accountLog in to calculate. You can explore the inputs and reference material below; results need a free student account.
Educational and decision-support tool only. Does not replace the current CAP protocol, WHO classification, or professional pathologist judgment.
Reference
Not graded
Clear cell carcinoma, malignant Brenner tumor, un-/dedifferentiated carcinoma, mesonephric-like carcinoma, and carcinosarcoma are not graded.
Serous carcinoma is also not graded — low-grade and high-grade serous carcinoma are distinct tumor types, not low- and high-grade variants of one tumor.
Endometrioid carcinoma — FIGO grading
Graded per the FIGO system used for endometrial endometrioid carcinoma. Notable nuclear atypia in the majority of tumor cells, evident at low power and discordant with the architectural grade, raises a Grade 1 or 2 tumor by one tier. Before upgrading, the possibility of high-grade serous carcinoma should be considered.
| Grade | Criterion |
|---|---|
| 1 | ≤5% non-squamous solid growth |
| 2 | 6–50% non-squamous solid growth |
| 3 | >50% non-squamous solid growth |
Mucinous carcinoma — Silverberg grading
Silverberg grading (prognostically significant) sums three parameters, each 1–3: predominant architecture (glandular/papillary/solid), nuclear atypia (mild/moderate/severe), and mitoses per 10 HPF (0–9/10–24/≥25, counted with a 10× wide-field eyepiece and 40× objective — field diameter 0.663 mm, area 0.345 mm² — counting only definite metaphase, anaphase, or telophase nuclei). Combined score 3–5 = Grade 1, 6–7 = Grade 2, 8–9 = Grade 3.
FIGO grading also exists for mucinous carcinoma but is not prognostically significant; its specific percentage criteria for mucinous carcinoma were not detailed in the supplied excerpt and are not reproduced here.
| Score | Architecture | Nuclear atypia | Mitoses / 10 HPF |
|---|---|---|---|
| 1 | Glandular | Mild | 0–9 |
| 2 | Papillary | Moderate | 10–24 |
| 3 | Solid | Severe | ≥25 |
Mucinous carcinoma — growth pattern-based grading
Growth pattern-based grading (confluent/expansile vs. infiltrative) has also been shown to associate with survival.
| Grade | Criterion |
|---|---|
| Low | Confluent/expansile growth, or ≤10% infiltrative growth |
| High | >10% infiltrative growth |
Immature teratoma — grading
The only malignant germ cell tumor that is graded. Graded on the number of low-power (40×) microscopic fields, in any one slide, containing aggregated immature neuroepithelium — the only immature element type counted for grading. A 2-tier system (low- vs. high-grade) has also been proposed as more reproducible: Grade 1 = low-grade; Grades 2–3 = high-grade.
Implants associated with immature teratoma must be separately assessed for immature elements. Although immature neuroepithelium is most common, implants may be entirely mature glial tissue (gliomatosis) instead.
| Grade | Low-power fields (40×) involved, any one slide |
|---|---|
| 1 (low-grade) | <1 field |
| 2 (high-grade) | 1–3 fields |
| 3 (high-grade) | ≥4 fields |
Sertoli-Leydig cell tumor — grading
3-tier WHO 2020 system based on Sertoli cell differentiation, tubular architecture, cytologic atypia, mitotic activity, and Leydig cell content. As differentiation of the Sertoli cell component decreases, tubular differentiation and Leydig cell number also decrease, while primitive gonadal stroma increases.
| Tier | Criteria |
|---|---|
| Well-differentiated | Sertoli cells lack significant atypia or mitotic activity; present in hollow or solid tubules, in association with readily identified clusters, cords, and single Leydig cells. |
| Moderately differentiated | Lobular pattern; Sertoli cells form nests, tubules, or cords with mild, moderate, or (rarely) bizarre cytologic atypia and modest mitotic activity; minimal Leydig cells at the periphery. |
| Poorly differentiated | Sarcomatous stroma resembling primitive gonadal stroma; sparse Leydig cells; associated with a minor component of moderately differentiated Sertoli-Leydig cell tumor. |
Sertoli-Leydig cell tumor — molecular context (not part of grading)
DICER1-mutant: younger patient age; moderately/poorly differentiated tumors; retiform or heterologous elements.
FOXL2 c.402C>G (p.Cys134Trp)-mutant: postmenopausal patients; moderately/poorly differentiated tumors; no retiform or heterologous elements.
DICER1/FOXL2 wild-type: intermediate patient age; no retiform or heterologous elements, including well-differentiated tumors.
Diagnostic pitfall: FOXL2 hotspot mutation is considered a hallmark of adult granulosa cell tumor. Its presence in tumors morphologically consistent with moderately/poorly differentiated Sertoli-Leydig cell tumor raises the possibility these represent adult granulosa cell tumors with luteinized stromal cell infiltrates mimicking Sertoli-Leydig cell tumor, rather than true Sertoli-Leydig cell tumors — correlate morphology with molecular findings.
DICER1 mutations are found only in moderately/poorly differentiated tumors — well-differentiated and moderately/poorly differentiated Sertoli-Leydig cell tumors may represent two distinct neoplasms with different DICER1 germline testing implications, analogous to low- and high-grade serous carcinoma.
Sources
1. Shimizu Y, Kamoi S, Amada S, et al. Toward the development of a universal grading system for ovarian epithelial carcinoma. Cancer. 1998;82(5):893-901. (Silverberg system.)
2. Busca A, Nofech-Mozes S, Olkhov-Mitsel E, et al. Histological grading of ovarian mucinous carcinoma — an outcome-based analysis. Histopathology. 2020;77(1):26-34.
3. Momeni-Boroujeni A, Song H, Irshaid L, et al. Outcome-based validation of confluent/expansile versus infiltrative pattern assessment and growth-based grading in ovarian mucinous carcinoma. Am J Surg Pathol. 2022;46(9):1250-1259.
4. Norris HJ, Zirkin HJ, Benson WL. Immature (malignant) teratoma of the ovary. Cancer. 1976;37(5):2359-2372.
5. O'Connor DM, Norris HJ. The influence of grade on the outcome of stage I ovarian immature (malignant) teratomas and the reproducibility of grading. Int J Gynecol Pathol. 1994;13(4):283-289.
6. Cheung AN, Ellenson LH, Gilks CB, et al. Tumours of the ovary. In: WHO Classification of Tumours Editorial Board. Female Genital Tumours. 5th ed. Lyon, France: IARC; 2020.
7. Karnezis AN, Wang Y, Keul J, et al. DICER1 and FOXL2 mutation status correlates with clinicopathologic features in ovarian Sertoli-Leydig cell tumors. Am J Surg Pathol. 2019;43(5):628-638.
8. College of American Pathologists. Protocol for the Examination of Specimens From Patients With Carcinoma of the Ovary, Fallopian Tube, or Primary Peritoneum (document Ovary_FT_Perit_1.5.0.0.REL_CAPCP).
Additional references in the source excerpt (de Kock et al., McCluggage et al., Shah et al., McConechy et al.) support specific DICER1/FOXL2 molecular findings and are not all individually reproduced here — consult the complete published protocol for exact citations.