abstract
Seromucinous neoplasms are a new category of ovarian epithelial tumor in
the
revised World Health Organization Classification of Tumours of the
Female Reproductive Organs. Borderline variants are well described, but
there have been few reports of seromucinous carcinomas. We report the
clinicopathologic features in 19 cases of ovarian seromucinous carcinoma
in patients aged 16 to 79 years (
mean 47). In 16 cases, the neoplasm
was unilateral and in 3 cases bilateral. The tumors ranged in size from
1.8 to 18 cm (mean 10.5 cm).
The tumors were stage I (n=15), stage II
(n=1), and stage III (n=3). The histologic features were highly variable
both within and between individual tumors. The majority of neoplasms
(12 cases) exhibited a predominant papillary architecture with lesser
components of glandular, microglandular, and solid growth. A predominant
glandular architecture was present in 6 cases, whereas 1 had a
predominantly solid growth.
A characteristic feature was an admixture of
cell types. Most of the tumors (15 cases) were mainly composed of
endocervical-like mucinous cells, whereas in 4 cases there was
predominant endometrioid differentiation. Other cell types, present in
varying proportions, included hobnail cells, eosinophilic cells,
squamous cells,
clear cells, and signet-ring cells. An infiltrate of
neutrophil polymorphs was a prominent feature in most cases. Most cases
also exhibited areas of microglandular architecture with cytoplasmic
clearing and intraluminal polymorphs, the features closely resembling
cervical microglandular hyperplasia. Areas of stromal hyalinization,
adenofibromatous growth, and psammoma bodies were present in a minority
of cases.
Endometriosis was identified in the same ovary in 10 cases,
and in 10 there was a component of seromucinous
borderline tumor.
Thirteen, 5, and 1 tumor were of grades 1, 2, and 3, respectively (using
the FIGO grading system for endometrioid adenocarcinomas of the uterine
corpus). A synchronous uterine endometrioid adenocarcinoma was present
in 1 case. Immunohistochemically, there was positive staining with CK7
(17/17 cases),
estrogen receptor (16/16 cases), progesterone receptor
(6/7 cases),
CA125 (15/15 cases), PAX8 (8/8 cases), CEA (8/13 cases),
CA19.9 (8/9 cases), and WT1 (2/13 cases). CK20 and CDX2 were negative in
all cases tested (16 and 14, respectively). p53 showed “wild-type”
staining in 4/4 cases, and p16 was focally positive in 5/5 cases.
Follow-up information was available in 8 patients. Seven were alive with
no evidence of disease (follow-up 3 to 74 mo), whereas 1 patient who
initially presented with a stage IIB tumor died of disease at 192
months. Given the characteristic admixture of cell types and the
overlapping morphologic features with low-grade serous, mucinous, and
endometrioid neoplasms, the most appropriate categorization of
seromucinous carcinomas is uncertain, but we believe they are best
regarded as a distinct type of ovarian epithelial malignancy and are
most similar to endometrioid adenocarcinomas.
We recommend grading them
in an analogous manner to ovarian endometrioid adenocarcinomas.
