Female adnexal tumor of probable Wolffian origin (FATWO)

Ovary tumor
Other ovarian specific tumors
Female adnexal tumor of probable Wolffian origin (FATWO)

Authors: Elena Lucas, M.D., Wenxin Zheng, M.D.

Editor-in-Chief: Debra Zynger, M.D.

Topic Completed: 1 August 2018

Minor changes: 10 March 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed search: Female adnexal tumor of Wolffian origin

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Table of Contents

Cite this page: Lucas E, Zheng W. Female adnexal tumor of probable Wolffian origin (FATWO). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ovarytumorfatwo.html. Accessed May 29th, 2020.

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

ICD-10: D39.10 - Neoplasm of uncertain behavior of unspecified ovary
ICD-10: D39.11 - Neoplasm of uncertain behavior of right ovary
ICD-10: D39.12 - Neoplasm of uncertain behavior of left ovary
ICD-10: D39.8 - Neoplasm of uncertain behavior of other genital organs

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)

Radiology images

Images hosted on other servers:

CT and MRI: large mass

MRI: mass near ovary

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)

Clinical images

Images hosted on other servers:

Adnexal mass

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

AFIP images

Broad ligament tumor

Solid and cystic cut surface

Lobulated cut surface

Images hosted on other servers:

Large peritoneal mass

Mass arising from the fimbriae

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.

Nodular architecture

FATWO at low power

Tubular growth pattern

Tubules infiltrating stroma

Tubular and solid pattern

Trabecular pattern

Resembling endometrioid carcinoma

Tubules with eosinophilic secretions

Solid growth pattern

Malignant FATWO

CD10

Inhibin

Calretinin

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

Ultrasound Obstet Gynecol 2017;49:807, Taiwan J Obstet Gynecol 2017;56:382

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 answer #1

D. Tumor originated from mesonephric embryological remnants

Comment Here

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 answer #2

E. This is a female adnexal tumor of probable Wolffian origin (FATWO), which is typically positive for pancytokeratin and CD10.

Comment Here

Reference: Female adnexal tumor of probable Wolffian origin (FATWO)