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

Author: Elena Lucas, M.D.
Senior Author: Wenxin Zheng, M.D.
Editor-in-Chief Review: Debra Zynger, M.D.

Revised: 20 September 2018, last major update August 2018

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed search: Female adnexal tumor of Wolffian origin
Cite this page: Lucas, E. Female adnexal tumor of probable Wolffian origin (FATWO). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/ovarytumorfatwo.html. Accessed November 21st, 2018.
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-10 coding
  • D39.10: Neoplasm of uncertain behavior of unspecified ovary
  • D39.11: Neoplasm of uncertain behavior of right ovary
  • D39.12: Neoplasm of uncertain behavior of left ovary
  • D39.8: Neoplasm of uncertain behavior of other genital organs
Epidemiology
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
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

Images hosted on PathOut server:

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

Images hosted on PathOut server:

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
Negative stains
Electron microscopy description
Molecular / cytogenetics description
Differential diagnosis
Board review 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?

  1. Final diagnosis is based on ancillary studies
  2. Minimal nuclear atypia and low mitotic rate are predictive of benign behavior
  3. Patients often have virilizing symptoms
  4. Tumor originated from mesonephric embryological remnants
  5. Tumor originated from paramesonephric embryological remnants
Board review answer #1
D. Tumor originated from mesonephric embryological remnants
Board review 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?



  1. Calterinin and inhibin immunostains help to differentiate it from sex cord stromal tumors
  2. CD117+ tumors harbor c-kit mutation
  3. ER and PR immunostains help to differentiate it from endometrioid carcinoma
  4. FOXL2 mutation is present in majority of tumors
  5. 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.