Case #1 - Adnexal Mass

Case #1 - Adnexal Mass

 

 

QUESTIONS:

1) What do you need to know from the surgeon before rendering a diagnosis?
A.   Is there involvement of the contralateral ovary?
B.   Is there mucinous ascites?
C.   Does the appendix look normal?
D.   Is there a history of cancer?
E.   All of the above.

2) What feature is necessary for the diagnosis of a mucinous borderline ovarian tumor?
A.   High-grade cytologic features and mitotic activity.
B.   Greater than 10 mm² of confluent growth.
C.   Architectural complexity with epithelial stratification (not attributable to tangential sectioning).
D.   Small nests of tumor surrounded by reactive stroma.
E.   Papillary architecture with fibrovascular cores.

3) Which of the following is considered adequate sampling of this case?
A.   One section per centimeter of solid growth for tumors with less than 10cm of solid growth
B.   Sampling should concentrate in areas of solid growth and areas suspicious for capsular rupture or capsular exophytic growth.
C.   Two sections per centimeter of solid growth for tumors with more than 10cm of solid growth.
D.   A and B only.
E.   All of the above

 

ANSWERS:

1) E
2) C
3) E


DISCUSSION:

In the context of bilateral ovarian involvement, mucinous ascites, an abnormal-appearing appendix, or a history of gastrointestinal carcinoma, the diagnosis of a primary mucinous ovarian neoplasm should be made with great reservation.  Metastatic mucinous carcinomas to the ovary can be deceptively bland, mimicking mucinous borderline tumors, and even mucinous cystadenomas.  In this case, all of these clinical features were absent, and a diagnosis of borderline mucinous tumor was rendered.

Borderline and invasive components will most likely form intracystic papillations and solid growth, which is why these areas should be selected for the frozen section.  However, this diagnosis is achieved by the presence of a complex architectural pattern containing epithelial stratification greater than 3 cells thick.  In order to avoid overcalling tangential sections through a papillation, some pathologists require areas of stratification up to 7 to 8 cells thick.  

The complete intraoperative evaluation should account for the gross impression, as well. For example, a large smooth-walled cyst with a focal papillation demonstrating borderline features may be diagnosed as a mucinous tumor with focal epithelial proliferation .  This conveys that the lesion does not quite meet the quantitative criteria of a borderline lesion (greater than 10% of the total tumor).  In contrast, a tumor with numerous papillations and/or a solid component demonstrating only simple mucinous epithelium should warrant either submission of an additional section or a diagnosis of mucinous cystadenoma, cannot exclude a borderline lesion until further sectioning.

Although moderate cytologic atypia is usually present, severe atypia and increased mitotic activity may necessitate a diagnosis of intraepithelial carcinoma.  Areas composed of either confluent growth or small infiltrative nests measuring greater than 10mm² in any one focus, are considered mucinous carcinoma.  A confluent or infiltrative focus less than this is considered a microinvasive borderline tumor.

We take for granted that the surgeons at our institution will stage a borderline ovarian tumor with the understanding that an invasive process can only be excluded after thorough evaluation of the tumor.  In addition, peritoneal implants (invasive and non-invasive types) and positive washings can be present even in the absence of histologically documented invasion within the primary tumor.  In settings where experience with borderline tumors is limited, it may be prudent to add the descriptor at least to reflect this level of uncertainty at the time of intraoperative consultation.  

Thorough evaluation of any borderline ovarian tumor includes a section per centimeter of maximum dimension of solid growth (if it is less than 10 cm).  Due to the exponential total volume of a larger tumor, twice the amount should be submitted for a tumor greater than 10cm.  If there is an area suspicious for capsular rupture or surface involvement, this area should be documented and sampled, as it may portend extra-ovarian involvement.

If the tumor has a large smooth-walled cyst, this component does not have to be sampled as thoroughly, and it may be efficient to submit a section similar to the amniotic “membrane roll”.  Any concerning histologic features, including intraepithelial carcinoma, microinvasion, or extra-ovarian disease may justify submission of additional material.  Also, in the context of a mucinous ascites (pseudomyxoma peritonei) , even a normal appearing appendix should be removed and submitted entirely for histologic evaluation to exclude a primary appendiceal neoplasm.  A grossly negative omentum should be sampled at one section per two centimeters of greatest dimension.

For additional information, see the articles in Human Pathology Vol 35, No.8 (August 2004), which document the Borderline Ovarian Tumor Workshop sponsored by the NIH.  Web-based images based on this workshop are also available at http://borderlineovariantumors.pathology.uic.edu

Contributors: Molly Galgano, MD, Department of Pathology, University of Virginia (MTW2Y@virginia.edu)
Helen Cathro, MBChB, Department of Pathology, University of Virginia ( hpc4f@virginia.edu)