(Courtesy of Dr. Christopher Crum, Brigham and Women’s Hospital, Boston, Massachusetts.) lieborderlinetumors,whichexhibitlesscytologicatypiaandtypicallynostromalinvasion.Borderlinetumorsmayseedtheperitoneum,butfortunatelythetumorimplantsusuallyare“noninvasive.”Ingeneral,malignantseroustumorsspreadthroughouttheperitonealcavityandtoregionallymphnodes,includingperiaorticlymphnodes;distantlymphaticandhematogenousmetastasesareinfrequent.
The prognosis for patients with high-grade serous carcinoma is poor, even after surgery and chemotherapy, and depends heavily on the stage of the disease at diagnosis. The 5-year survival for women with carcinoma confined to one ovary is about 90%, but falls precipitously with higher stage tumors to less than 40% depending on the exact stage. In contrast, borderline tumors are associated with nearly 100% survival. Of note, women with tumors containing BRCA1/2 mutations tend to have a better prognosis than women whose tumors lack these genetic abnormalities.
Mucinous tumors differ from serous tumors in two respects: the neoplastic epithelium consists of mucin-secreting cells; and mucinous tumors are considerably less likely to be malignant. Overall, only 10% of mucinous tumors are malignant; another 10% are borderline, and 80% are benign.
MORPHOLOGYOngrossexamination,mucinoustumorsproducecysticmassesthatmaybeindistinguishablefromseroustumorsexceptbythemucinousnatureofthecystcontents.However,theyaremorelikelytobelargerandmulticystic(
Fig.19.17A ).Serosalpenetrationandsolidareasofgrowtharesuggestiveofmalignancy.Mucin-producingepithelialcellslinethecysts(
Fig.
19.17B ).Malignanttumorsarecharacterizedbysolidareasofgrowth,pilingup(stratification)ofliningcells,cytologicatypia,andstromalinvasion.
Comparedwithseroustumors,mucinoustumorsaremuchlesslikelytobebilateral.Thisfeatureissometimesusefulindifferentiatingmucinoustumorsoftheovaryfrommetastaticmucinousadenocarcinomafromagastrointestinaltractprimary(theso-called“Krukenbergtumor”),whichmoreoftenproducesbilateralovarianmasses.
Rupturedovarianmucinoustumorsmayseedtheperitoneum;however,thesedepositstypicallyregressspontaneously.Stableimplantationofmucinoustumorcellsintheperitoneumwithproductionofcopiousamountsofmuciniscalledpseudomyxomaperitonei;inmostcases,thisdisorderiscausedbymetastaticspreadoftumorsinthegastrointestinaltract,primarilytheappendix(Chapter15).
The prognosis of mucinous cystadenocarcinoma is somewhat better than that of its serous counterpart, although stage rather than histologic type (serous versus mucinous) is the major determinant of outcome. Mutations in KRAS are detected in approximately 50% of ovarian mucinous carcinomas, however this does not help distinguish them from metastatic GI tumors, which also have a high frequency of KRAS mutations.