Seromucinous Tumor of the Ovary Ming-Chieh Lin 林明杰

Ovarian Mucinous Tumors Definition Taditional: Ovarian tumors some or all of whose epithelial cells contain intracytoplasmic mucin Endocervix (endocervical-like, Mullerian type) Gastrointestinal 2014 WHO Mucinous tumor Gastrointestinal epithelium Seromucinous tumor Endocervical-type mixed with serous or other Mullerian cell types

Ovarian Seromucinous Tumors Classification: ICD-O codes Benign Seromucinous cyatadenoma 8474/0 Seromucinous adenofibroma 9014/0 Borderline Seromucinous borderline tumor 8474/1 Malignant Seromucinous carcinoma 8474/3

Benign Seromucinous Tumors Definition: A benign ovarian tumor with endocervical-type mucinous and tubal-type (serous) cells or more Mullerian cell types, all accounting for at least 10% of the epithelium. Synonym Seromucinous cystadenoma (adenofibroma) Mullerian cystadenoma of mixed cell types

Benign Seromucinous Tumors Epidemiology 1% of benign epithelial neoplasms Peak age: late reproductive age Clinical features Non-specific Usually diagnosed incidentally

Benign Seromucinous Tumors Macroscopy Unilocular cyst Serous or mucoid fluid Microscopy Variable admixtures of serous and mucinous (endocervical-type) Endometrioid, transitional, squamous

Benign Seromucinous Tumors Histogenesis Likely from endometriosis Prognosis and predictive factors Benign

Seromucinous Borderline Tumors Definition A non-invasive, proliferative epithelial tumor composed of more than one epithelial cell type, most often serous and endocervical-type mucinous; however, endometrioid, and less often, clear cell, transitional or squamous may be seen Synonyms Endocervical-type mucinous borderline tumor Mullerian mucinous borderline tumor Atypical proliferative Mullerian tumor

Seromucinous Borderline Tumors Epidemiology 15% of all mucinous borderline tumor In the past, these tumors have been considered a subset of mucinous tumor (endocervical type) Clinical features Average age: 34-44 y/o Non-specific S/S Most are FIGO stage I Rare advanced stage Implants and/or lymph node involvement

Seromucinous Borderline Tumors Macroscopy Mean size: 8-10 cm Typically unilocular, viscid fluid Papillary projections Often associated with endometriosis Bilateral: 40%

Seromucinous Borderline Tumors Microscopy Architectural features similar to serous borderline tumors Complex papillary architecture branching in a hierarchical manner into progressively smaller papillae Terminating in small detached epithelial tufts Larger papillae Edematous stroma with neutrophils

Seromucinous Borderline Tumors Microscopoy Epithelial lining Stratified Low grade nuclear atypia Most are endocervical-type mucinous or serous cells Endometrioid, squamous, transitional, clear cells Goblet cells (-) Often associated with endometriosis Immunohistochemistry CK7(+)/CK20(-)/CDX-2(-) ER(+)/PR(+)

Serous borderline tumor-100X

Resembling a serous borderline tumor with bulbous papillae The papillae are lined by stratified endocervical-like mucinous cells The papillae are line by stratified eosinophilic cells, with numerous PMN in the papillae and mucin

Seromucinous Borderline Tumors Histogenesis Data is limited Associated with endometriosis, at least 1/3 cases Mucinous metaplasia ER (+) Similar to endometrioid tumor ARID1A mutation (loss of expression): 1/3 Similar to endometrioid and clear cell carcinoma

Seromucinous Borderline Tumors Prognosis and predictive factors Good outcome even with peritoneal implants

Endometriosis-associated Tumor Endometrioid tumor Clear cell tumor Seromucinous tumor

Seromucinous Carcinoma Definition A carcinoma composed predominantly of serous and endocervical-type mucinous epithelium. Foci of clear , endometrioid and squamous cells Synonyms Endocervical-type mucinous carcinoma Mixed epithelial carcinoma of Mullerian type

Seromucinous Carcinoma Epidemiology Quite uncommon Data not available Clinical features Mean age: 45 y/o

Seromucinous Carcinoma Macroscopy Mean tumor size: 12 cm Bilateral: >50% Unilocular or multilocular with papillary projections and solid areas

Seromucinous Carcinoma Microscopy Lack of consensus on diagnostic criteria Immunohistochemically Similar to seromucinous borderline tumor

Seromucinous Carcinoma Prognosis and predictive factors Data limited In one series of 54 cases (Am J Surg Pathol. 2002, 26(12):1529-1541) Stage I: outcome is favorable Advanced stage: 50% die of disease

聯醫1589521 Right ovarian cyst Laparoscopic oophorectomy 40-year-old female Right ovarian cyst Laparoscopic oophorectomy Unilocular cyst, 7 x 5 x 5 cm Multiple small papillary projections

FS-100x-Cyst with papillary projections

PMN FS-200X Endocervical epithelium Epithelial proliferation

FS-200X-epithelial proliferation

聯醫1589521-Frozen Section Right ovary, frozen section: Mucinous borderline tumor, endocervical-like type (Seromucinous borderline tumor)

40X-Cyst with papillary projections

40X-Cyst with papillary projections

200X-endocervical epithelium

400X-ciliated cells

200X-epithelial proliferation

200X-epithelial proliferation

400X-Inflammatory cells

200X-Endometriosis CD10

400X-Atypical endometriosis

CK7-100X CK7-200X

CK20-100X

ER-200X

聯醫1589521 Ovary, right, laparoscopic oophorectomy Mucinous borderline tumor, endocervical type (Seromucinous borderline tumor), associated with endometriosis