Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Etiology | Clinical features | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Lucas E, Zheng W. Female adnexal tumor of probable Wolffian origin. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ovarytumorfatwo.html. Accessed January 25th, 2021.
Definition / general
- Adnexal tumor arising from remnants of Wolffian (mesonephric) duct
Essential features
- Adnexal tumors arising from mesonephric (Wolffian duct) remnants
- Heterogeneous histologic appearances
- Diagnosis based predominantly on the anatomical site and morphology
Terminology
- Female adnexal tumor of probable Wolffian origin (FATWO)
- Wolffian adnexal tumor (WAT)
- Also known as Wolffian tumor, Wolffian adenoma and retiform Wolffian adenoma
ICD coding
Epidemiology
- Rare, approximately 100 cases reported (Oncol Lett 2017;14:5167)
- Median age 50 years, range 15 - 87 years (Int J Surg Pathol 2008;16:222)
Sites
- Broad ligament (most common site)
- Mesosalpinx
- Ovaries
- Fallopian tubes
- Paravaginal
- Peritoneum
Etiology
- Originates from mesonephric (Wolffian) duct remnants
- Arise along the trajectory of the Wolffian duct: from the ovarian hilum, along mesosalpinx, broad ligament, lateral aspects of the uterus and cervix, to the outer third of the vagina (Hum Pathol 1999;30:856)
- No disease specific mutations or genetic alterations identified
Clinical features
- Adnexal mass with nonspecific symptoms or an incidental finding
- Complaints include lower abdominal pain / distention, pelvic mass, abnormal vaginal bleeding or ascites
- Most tumors hormonally inert; rare tumors hormonally active causing endometrial hyperplasia (Gynecol Oncol 1995;59:304)
- Most tumors are unilateral; rarely bilateral
Radiology description
- Well defined, encapsulated, lobulated or ovoid mass, often separate from ovaries, tubes and uterus
- May demonstrate solid and cystic areas
- Low signal intensity rim around the tumor on T2 weighted MRI images might be a characteristic feature (J Obstet Gynaecol Res 2016;42:1046)
Prognostic factors
- Low malignant potential; most tumors behave in a benign fashion
- Recurrence or metastases occur in 11 - 20% of cases; median 48 months to recurrence (range 13 - 96 months) (Gynecol Oncol 2002;86:225)
- Adverse prognostic factors: large size (> 10 cm), capsular invasion and rupture with tumor implants (Histopathology 2005;46:716)
- Aggressive behavior includes extrauterine spread, recurrence or distant metastasis, typically to the liver and lungs (Gynecol Oncol 2002;86:225)
- High cellularity, nuclear pleomorphism and high mitotic activity are associated with worse prognosis but tumors with minimal nuclear atypia and low mitotic rate may recur; no single feature is predictive of malignant behavior (Tohoku J Exp Med 1997;181:371)
Case reports
- 15 year old girl with a painful pelvic mass (Int J Gynecol Cancer 2004;14:546)
- 30 year old woman with an incidental ovarian mass (Gynecol Oncol Rep 2014;10:22)
- 37 year old woman with abdominal pain and adnexal mass (Oncol Lett 2017;13:3403)
- 50 year old woman with bilateral adnexal masses (Int J Gynecol Pathol 2018;37:331)
- 60 year old woman with an abdominal mass (Arch Pathol Lab Med 2000;124:431)
- 70 year old woman with an abdominal mass (Indian J Pathol Microbiol 2014;57:620)
- 76 year old woman with a retroperitoneal mass (Histopathology 2005;46:716)
- 87 year old woman with uterine endometrioid carcinoma and an incidental ovarian mass (Int J Surg Pathol 2008;16:222)
Treatment
- Hysterectomy and bilateral salpingo-oophorectomy; tumor debulking
- Role of adjuvant chemotherapy or radiation therapy is unknown
- For recurrent / metastatic c-kit (CD117) expressing tumors, tyrosine kinase inhibitor Gleevac (STI571) is a treatment option (Int J Gynecol Cancer 2004;14:546)
Gross description
- Size from < 1 cm to > 25 cm
- Encapsulated mass, often nodular, lobulated appearance
- Often centered within or hanging from broad ligament or fallopian tube by a pedicle
- Solid or partially cystic; may have spongy appearance
- Cut surface rubbery, variegated, pale yellow, gray-white or tan
- May be hemorrhagic or necrotic
Gross images
Microscopic (histologic) description
- Cribriform, tubular, cystic, tubulocystic, sieve-like, solid cords and diffuse growth patterns
- Usually a single pattern predominates but several architectural patterns may coexist (Am J Surg Pathol 1983;7:125)
- Solid sheets of spindle or polygonal cells may be the dominant morphology
- Fibrous stroma varies from scant to large areas of hyalinization
- Intraluminal bright eosinophilic secretions often present
- Cells are columnar or cuboidal, may have scant clear cytoplasm, flat or hobnail appearance
- Large cytoplasmic vacuoles and signet ring cell-like forms may be seen (Int J Surg Pathol 2008;16:222)
- Uniform, round or oval nuclei with pale, evenly dispersed chromatin; may have nuclear grooves
- Nuclear atypia is mild to moderate
- Mitotic activity is typically low (up to 1/10 - 3/10 high powered fields)
- Malignant tumors may present as undifferentiated carcinoma, high cellularity, pleomorphic nuclei or show increased mitoses (up to 16/10 high powered fields) (Am J Surg Pathol 1983;7:125)
Microscopic (histologic) images
Contributed by Elena Lucas, M.D. and Wenxin Zheng, M.D.
Positive stains
- Pancytokeratin (AE1 / AE3, CAM5.2), CK7, CK19, CD10 (50 - 100%)
- Variable calretinin, inhibin, MelanA, CD99, WT1, ER, PR, androgen receptor, EMA, GATA3, CD117 (c-kit), vimentin, SMA (in spindle cell areas)
Negative stains
- PAX8, CK20, CEA, SF1 (Int J Gynecol Pathol 2016;35:167)
Electron microscopy description
- Distinct basal laminae, desmosomal junctions and poorly developed cytoplasmic organelles (Pathol Int 2006;56:95)
- No / minimal cilia, no secretory granules (Pathol Int 2006;56:95)
Molecular / cytogenetics description
- No disease defining molecular alterations identified
- Reported CTNNB1, MET, PIK3CA, BRAF and CDKN2A mutations (Int J Gynecol Pathol 2017;36:575); STK11 and ARID1B mutations and variants of unknown significance in KMT2D (Int J Gynecol Pathol 2018 Aug 21 [Epub ahead of print])
- Despite CD117 positivity in some tumors, no c-kit mutations have been detected (Pathol Int 2006;56:95)
Differential diagnosis
- Endometrioid carcinoma: glandular pattern with variable squamous differentiation, nuclear atypia, may show intraluminal mucin; positive for PAX8
- High grade serous carcinoma: papillary and micropapillary architecture, high grade nuclear features, high mitotic activity; positive for PAX8, diffuse positive or absent p53
- Clear cell carcinoma: high grade nuclear features; positive for PAX8
- Sertoli cell tumor (SCT) and Sertoli-Leydig cell tumors (SLCT): androgenic or estrogenic manifestations; presence of Leydig cells (in SLCT); negative for CD10, positive for SF1; DICER1 mutation in moderately and poorly differentiated SLCT (Am J Surg Pathol 2017;41:1178)
- Adult granulosa cell tumor: typically solid pattern, pale, angulated cells with nuclear grooves; hyperestrogenism; negative for CD10; FOXL2 mutation (FOXL2 immunohistochemistry is not specific for mutation status) (N Engl J Med 2009;360:2719)
- Adenomatoid tumor: small, unencapsulated tumor; lacks variety of patterns within the same tumor; positive for WT1, negative for CD10
- Mesothelioma: lacks variety of patterns within the same tumor; positive for WT1, negative for CD10
- Metastatic carcinoma: higher nuclear grade, typically lacks variety of patterns, often shows necrosis; often positive for CEA
Additional references
Board review style question #1
A 48 year old woman is diagnosed with a 6 cm adnexal mass arising from the broad ligament. She undergoes salpingo-oophorectomy. Microscopically, the tumor has a nodular appearance with low grade cells arranged in a sieve-like pattern and tightly packed tubules with eosinophilic secretions. No necrosis is seen. Mitotic activity is 1/10 high powered fields. The tumor cells are negative for PAX8 and positive for CD10. Which of the following is likely to be true?
- Final diagnosis is based on ancillary studies
- Minimal nuclear atypia and low mitotic rate are predictive of benign behavior
- Patients often have virilizing symptoms
- Tumor originated from mesonephric embryological remnants
- Tumor originated from paramesonephric embryological remnants
Board review style answer #1
D. Tumor originated from mesonephric embryological remnants
Comment Here
Reference: Female adnexal tumor of probable Wolffian origin (FATWO)
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Reference: Female adnexal tumor of probable Wolffian origin (FATWO)
Board review style question #2
This image is from a 50 year old woman with an encapsulated adnexal mass found incidentally. Which of the following statements is true?

- Calterinin and inhibin immunostains help to differentiate it from sex cord stromal tumors
- CD117+ tumors harbor c-kit mutation
- ER and PR immunostains help to differentiate it from endometrioid carcinoma
- FOXL2 mutation is present in majority of tumors
- Tumor is typically positive for pancytokeratin and CD10
Board review style answer #2
E. This is a female adnexal tumor of probable Wolffian origin (FATWO), which is typically positive for pancytokeratin and CD10.
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Reference: Female adnexal tumor of probable Wolffian origin (FATWO)
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Reference: Female adnexal tumor of probable Wolffian origin (FATWO)