Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_100_библиотеки_им_акад_М_И_Перельмана
.pdf
Molar Pregnancy, Pathology of the Placenta 319
https://t.me/med1917
• Outcome
Persistent GTD (intrauterine recurrence, uterine myoinvasion, extrauterine spread, or gestational choriocarcinoma) may occur in 15–20%
of CHM and in up to 5% of PHM. Dispermic
CHM appear to carry a higher risk for persistent GTD than monospermic CHM.
Macroscopy
The macroscopic features depend on the gestational age. Second trimester CHM consists of
clusters of innumerable uniformly enlarged thinwalled translucent chorionic villi whereas the chorionic villi in early first trimester CHM usually
appear normal. The chorionic villi in PHM may
appear normal or focally enlarged. Fetal tissue
may be present in PHM.
Microscopy
Second trimester CHM exhibits uniformly
enlarged chorionic villi, villous cisterns, villous
mesenchymal apoptosis, exuberant villous trophoblast proliferation, and variable degrees of extravillous trophoblast atypia. The extent of such
features may be limited in early first trimester
CHM. PHM exhibits a dual population of enlarged
irregular chorionic villi with scalloped borders,
villous inclusions and villous cisterns and smaller
fibrotic chorionic villi. Villous trophoblast proliferation is patchy and limited in extent.
Immunophenotype
p57 immunostaining is helpful if the morphologic
features raise consideration of CHM, which contains only paternal DNA (diandric diploid genotype). p57 is only transcribed by the maternal
copy of the p57 gene and therefore immunoexpression is detected in non-molar gestations and in
PHM (diandric triploid genotype). However, p57
staining is absent in the villous cytotrophoblast
and villous mesenchyme of CHM. p57
immunostaining does not discriminate PHM
from non-molar gestations; genotype testing is
needed in that differential diagnosis.
Molecular Features
Short tandem repeat genotype testing is the reference standard for diagnosing molar pregnancy
and can be performed in formalin-fixed, paraffinembedded tissue. Most CHM exhibits diandric
diploid genotype; paternal tetraploidy has been
described in case reports. Rarely, an inherited
form of CHM that exhibits biparental diploidy
occurs in the setting of NLRP7 or KHDC3L mutation. PHM exhibits diandric triploid genotype.
Since digynic triploid genotype is not considered
a PHM, the use of DNA ploidy testing, which can
detect triploidy but cannot distinguish the relative
parental versus maternal DNA contr ibution, is
insufficient to diagnose PHM.
Differential Diagnosis
Non-molar fetal aneuploidy, hydropic degeneration of non-molar gestation, and placental mesenchymal dysplasia may exhibit abnormal villous
morphology that mimics early first trimester
CHM and PHM.
References and Further Reading
American College of Obstetricians and Gynecologists
Committee on Practice Bulletins. Diagnosis and treatment of gestational trophoblastic disease. ACOG Prac-
tice Bulletin 53, June 2004, reaffirmed 2014.
Banet, N., DeScipio, C., Murphy, K. M., Beierl, K.,
Adams, E., Vang, R., & Ronnett, B. M. (2014). Characteristics of hydatidiform moles: Analysis of a prospective series with p57 immunohistochemistry and
molecular genotyping. Modern Pathology, 27,
238–254.
Buza, N., & Hui, P. (2013). Partial hydatidiform mole:
Histologic parameters in correlation with DNA
genotyping. International Journal of Gynecological
Pathology, 32, 307–315.
Vang, R., Gupta, M., Wu, L. S., Yemelyanova, A. V.,
Kurman, R. J., Murphy, K. M., Descipio, C., &
Ronnett, B. M. (2012). Diagnostic reproducibility of
hydatidiform moles: Ancillary techniques (p57
M
320 Mucinous Tumors, Pathology of the Ovary
https://t.me/med1917
immunohistochemistry and molecular genotyping)
improve morphologic diagnosis. American Journal of
Surgical Pathology, 36, 443–453.
WHO Classification of Tumours Editorial Board. (2020).
Female genital tumours (WHO classification of
tumours series, 5th ed., Vol. 4). International Agency
for Research on Cancer. https://publications.iarc.fr/592
Mucinous Tumors, Pathology
of the Ovary
Pavel Dundr, Nikola Hájková, Michaela Bártů,
Kristýna Němejcová and Ivana Stružinská
Institute of Pathology, First Faculty of Medicine,
Charles University and General University
Hospital, Prague, Czechia
Mucinous Cystadenoma and
Adenofibroma
Definition
Benign epithelial tumors showing mucinous differentiation, consisting of a gastric foveolar-type,
intestinal with goblet cells, or of a Müllerian-type
epithelium.
Clinical Features
• Incidence
These tumors are not common and
account for approximately 80% of all primary ovarian mucinous tumors. Mucinous
cystadenoma is more common than m ucinous cystadenofibroma.
• Age
These tumors occur at a wide age range
(median age is 50 years).
• Symptoms
Symptoms are mostly related to abdominal or
pelvic mass. Pelvic pain.
• Outcome
These tumors are benign.
Macroscopy
Mucinous cystadenomas are usually unilateral
multilocular cystic lesions with a mean size of
10 cm; however, some tumors can be very large
(>30 cm) (Fig. 1a, b).
Microscopy
Mucinous cystadenomas are characterized by
multiple cystic and glandular structures (Fig. 2).
The epithelial lining consists of benign mucinous
epithelium which is of a gastric foveolar-type,
intestinal with goblet cells, or of a Müllerian
type. Adenofibromatous lesions are rare and macroscopically usually smaller. Histologically, the
lesions are characterized by glandular structures
composed of the same epithelium as
cystadenomas, located in fibromatous stroma of
variable density. By definition, the epithelium is
simple, non-stratified without atypia, but papillary
proliferations can rarely be found. Mitotic figures
are usually absent, but rare mitoses can be seen,
especially in the crypts.
Immunophenotype
Not clinically relevant.
Molecular Features
Not clinically relevant. Up to 50% of benign
mucinous cystadenomas carry KRAS mutations.
Loss of heterozygosity (LOH), homozygous deletions, or mutations in the tumor suppressor gene
CDKN2A can be found approximately in 50% of
tumors.
Differential Diagnosis
Tumors with focal increased epithelial proliferation should be differentiated from mucinous borderline tumor. The arbitrary criterion for
mucinous borderline tumor is epithelial proliferation in >10% of the epithelial volume. Otherwise,
the tumor should be classified as mucinous
cystadenoma with increased epithelial
proliferation.
Mucinous Borderline Tumor
Synonyms
Not recommended: Atypical proliferative mucinous tumor; mucinous tumor of low malignant
potential.
Mucinous Tumors, Pathology of the Ovary 321
https://t.me/med1917
Mucinous Tumors, Pathology of the Ovary, Fig. 1 Benign mucinous cystadenoma of the ovary. Note the intact
capsule (a) and multiple cysts on cut surface (b)
Definition
Non-invasive mucinous tumors with gastrointestinal differentiation, increased epithelial proliferation, and complex architecture.
Clinical Features
• Incidence
These tumors are not common. They represent
the second most common ovarian borderline
tumor type in Europe and North America. In
Asia, they are the most common ovarian borderline tumor type.
• Age
These tumors occur at a wide age range
(median age is 45 years).
• Symptoms
Symptoms are mostly related to abdominal or
pelvic mass. Pelvic pain.
• Treatment
Surgical treatment with R0 resection is
desirable.
• Outcome
The prognosis is excellent. The overall survival
rate for patients with mucinous borderline
tumor is 95–100%. The recurrence rate is low.
Macroscopy
Mucinous borderline tumors are usually large
tumors (mean size 20 cm, rare cases up to
50 cm) with a smooth external surface. On the
cut surface, the tumors are multilocular cystic
with mucinous content. Solid areas can also be
found. Most cases are unilateral.
Microscopy
Mucinous borderline tumors (MBTs) are characterized by increased proliferation of
gastrointestinal-type epithelium (either resembling gastric epithelium of pyloric type, or intestinal epithelium with goblet cells and rarely
Paneth cells) with complex architecture (Fig. 3).
Intestinal differentiation with goblet cells occurs
in a minority of cases, and in most cases, the
epithelium is of gastric (pyloric) or
pancreatobiliary type, rather than intestinal.
Nuclear atypia is usually mild to moderate and
there can be increased mitotic activity (especially
in the crypts, but also in the surface epithelium).
Areas of necrosis can be found and should not be
regarded as a sign of malignancy, because they
M
322 Mucinous Tumors, Pathology of the Ovary
https://t.me/med1917
Mucinous Tumors, Pathology of the Ovary,
Fig. 2 Benign mucinous cystadenoma consisting of
bland epithelium with mild pseudostratification (a). There
is prominent stromal luteinization in the vicinity of the
rather represent ischemic necrosis related to torsion or localized ischemia.
Cases with substantial nuclear atypia are clas-
sified as MBT with intraepithelial carcinoma, but
the clinical signifi cance of such changes is not
clear. MBTs are commonly heterogeneous with
areas of benign mucinous cystadenoma and/or
adenofibroma, and only cases with areas of
increased proliferation exceeding 10% of the
examined epithelial volume should be classified
as mucinous borderline tumo r. Otherwise, the
tumor is c lassified as a mucinous cystadenoma
with focal epithelial proliferation. Due to the
heterogeneity of mucinous tumors, adequate
sampling is needed to exclude mucinous carcinoma, which is definedasatleast1sectionper
1 cm of tumor diameter in tumors measuring up
to 10 cm, and 2 sections per 1 cm of diameter in
tumors 10 cm. Microinvasion, defined as a
focus or multiple foci with each single focus
measuring <5 mm in greatest dimension, can
tumor (b). Benign mucinous cystadenoma arising in
benign Brenner tumor (c). Leakage of mucinous material
into the ovarian stroma in benign mucinous cystadenoma
(the so-called pseudomyxoma ovarii) (d)
be found in the form of single cells, groups or
glands, and is usually associated with stromal
reaction. The lesional cells in microinvasive
areas share either the same cytological features
as mucinous borderline tumor (mucinous borderline tumor with microinvasion), or display
marked nuclear atypia (MBT with microinvasive
carcinoma). The MBTwith microinvasion shows
recurrence and death related to disease in <5% of
cases. The clinical significance of microinvasive
carcinoma currently lacks evidence (Ferrero
et al., 2012).
Immunophenotype
MBT has the same immunophenotype as mucinous carcinoma (see Mucinous Carcinoma).
Molecular Features
Molecular aberrations occurring in MBT include
mutations of KRAS (50–65%), CDKN2A
(10–15%), and TP53 (0–33%) (Dundr et al.,
Mucinous Tumors, Pathology of the Ovary 323
https://t.me/med1917
Mucinous Tumors, Pathology of the Ovary,
Fig. 3 Mucinous borderline tumor (MBT) with papillary
and glandular arrangement (a). Higher magnification of
MBT showing gastric-type epithelium with mild nuclear
atypia and increased epithelial proliferation (b). MBTwith
2023a; Hunter et al., 2012). These aberrations are
similar to those found in mucinous cystadenoma
and mucinous carcinoma. The only difference
between MBT and mucinous carcinoma seems to
be TP53 mutation, which is more common in
mucinous carcinoma, and ERBB2 amplification,
which occurs less frequently in MBT (5–20%)
than in mucinous carcinoma (up to 43%)
(Anglesio et al., 2013; Dundr et al., 2023a;
M
intestinal-type epithelium with goblet cells (c). MBT with
anaplastic carcinoma mural nodule (d). Cytokeratin
20 expression seen in most tumor cells (e). Synaptophysin
expression in multiple neuroendocrine cells within the
epithelium of MBT (synaptophysin) (f)
Chang et al., 2016; Chao et al., 2014; McAlpine
et al., 2009).
Differential Diagnosis
The main differential diagnosis of primary ovarian MBT includes the distinction from mucinous
carcinoma and tumors of metastatic origin. The
differential diagnosis with metastatic tumors is
described in detail in “Mucinous Carcinoma”
324 Mucinous Tumors, Pathology of the Ovary
https://t.me/med1917
section. The distinction between MBT with typical features is generally not
problematic. However, some cases can show
high-grade nuclear atypia and markedly increased
epithelial proliferation and the distinction
between MBT and mucinous carcinoma with
expansile invasion can be problematic (Dundr
et al., 2023a). However, contrary to MBT, mucinous carcinoma with expansile pattern of invasion
is characterized by marked crowding of wellformed glands or interconnecting epithelial
branching and papillary proliferation, with a substantial reduction or absence of intervening
stroma and forming a maze-like pattern. Cases of
MBT with high-grade nuclear atypia but otherwise typical architecture are classified as MBT
with intraepithelial carcinoma (Chen et al., 2020).
Tumors with mural nodules should be consid-
ered in differential diagnosis of mixed and collision tumors. Mural nodules can rarely be f ound
in all types of mucinous t umors, and these may
be malignant (anaplastic carcinoma or, exceptionally, true sarcoma) (Fig. 3d)orprobably
benign (sarcoma-like), but the follow-up data
concerning sarcoma-like mural nodules are still
limited (Hamada et al., 1995; Nakamura et al.,
1998;Prat&Scully,1979). The most com mon
type of mural nodules are anaplastic carcinoma
mural nodules which can be of the sarcomatoid,
rhabdoid, or pleomorphic subtype, but the epithelial component should be present at least
focally. Sarcomatous mural nodules are usually
high-grade lesions characterized by a monomorphous proliferation of atypical spindle cells.
Rarely leiomyosarcoma, rhabdomyosarcoma,
and osteosarcoma have also been described.
Sarcoma-like nodules are usually small and
sharply demarcated. Histologically, epulis-like,
pleomorphic, spindle cell, and giant cell histiocytic subtypes are recognized. The histogenesis
of mural nodules is not entirely clear. The limited
data suggest that anaplastic carcinoma mural
nodules represent a dedifferentiation from
mucinous tumors, in which the TP53 mutation
plays a crucial role. True sarcoma mural nodules
may also represent independent (“collision”)
tumors. Finally, sarcoma-like mural nodules can
be reactive benign lesions.
Mucinous Carcinoma
Definition
Invasive mucinous tumor consisting of
gastrointestinal-type epithelium.
Clinical Features
• Incidence
Primary mucinous carcinoma (MC) of the
ovary is a rare tumor representing approximately 3% of all ovarian cancers (Lee &
Scully, 2000; Seidman et al., 2003). Previously, the incidence of MC was reported as
much higher, accounting for about 12% of all
ovarian carcinomas. However, the data from
the last two decades showed that a significant
proportion of tumors classified as primary
ovarian MC are actually metastases with the
primary source located most commonly in the
gastrointestinal tract.
• Age
Median age of occurrence is 55 years.
• Symptoms
Patients with MC usually present with nonspecific symptoms related to abdominal mass.
Most tumors are confined to ovary (stage I).
Advanced tumors are at the time of
diagnosis rare.
• Treatment
Depending on the stage. Surgical treatment
with R0 resection is desirable.
• Outcome
The most important prognostic factor is the
stage of the disease. Most MC (up to 80%)
are diagnosed in the early stage and their prognosis is excellent, with more than a 90% 5-year
overall survival. However, the prognosis of
advanced disease is poor, and the most important prognostic factor for these tumors is the
presence of residual disease after cytoreductive
surgery.
Macroscopy
Most primary ovarian MC are large (>10 cm or
>15 cm), unilateral, multilocular solid, and cystic
tumors with intact smooth surface, without apparent nodularity. Cystic and solid areas in these
Mucinous Tumors, Pathology of the Ovary 325
https://t.me/med1917
tumors are evenly distributed throughout the
tumor.
Microscopy
MC is characterized by the presence of
gastrointestinal-type epithelium, which is mostly
of the gastric (pyloric) or pancreatobiliary type.
Intestinal differentiation with goblet cells occurs
in a minority of cases. The defining feature of MC
is the presence of invasion in at least 5 mm in the
largest linear extent. There are two types of invasion – expansile and infiltrative (Chen et al.,
2005). The predominant type of invasion is usu-
ally expansile, while the infiltrative type of invasion is absent or only focal in most cases. The
expansile type of invasion is defined as a marked
glandular crowding of well-formed glands or
interconnected epithelial branching and papillary
proliferation with a substantial reduction or
absence of intervening stroma (Fig. 4a, b). The
desmoplastic stromal reaction is absent. However,
the interpersonal diagnostic agreement in the
assessment of this type of invasion is poor, and
the differential diagnosis between primary ovarian MC with an expansile type of invasion and
MBT may be very challenging in some cases.
Infiltrative invasion is characterized by the
destructive growth of irregular glands, nests, or
isolated cells with malignant cytological features
usually associated with a desmoplastic stromal
reaction (Fig. 4c, d). This type of invasion is
rare, and in cases with infiltrative invasion, the
possibility of a metastatic origin should be considered in the differential diagnosis. This is especially true for tumors with a signet ring cell
component, which is present only rarely in primary ovarian MC. Due to the fact that areas with
features of benign mucinous cystadenoma or
MBT are common in MC, adequate sampling of
all mucinous tumors is needed (1 section per 1 cm
of diameter for tumors up to 10 cm, 2 sections per
1 cm of diameter for larger tumors).
The grading of primary ovarian MC is not
mandatory and there is insufficient evidence for
Mucinous Tumors, Pathology of the Ovary, Fig. 4 Mucinous carcinoma (MC) of the ovary with expansile type of
invasion (a, b). Note the architectural complexity and reduced stroma. MC with infiltrative type of invasion (c, d)
M
326 Mucinous Tumors, Pathology of the Ovary
https://t.me/med1917
its use in decisions regarding adjuvant treatment
(Busca et al., 2019). The new WHO Classification
of Female genital tumors (2020) does not mention
the grading of MC at all. However, there are
basically four possible approaches for MC grading: (i) FIGO grading based on the same criteria as
for endometrioid carcinoma grading (primarily
architecture-based with G1 showing 5%, G2
6–50%, and G3 > 50% of solid growth; the presence of severe nuclear atypia in >50% of tumor
cells increases the grade by one level) – although
this grading system does not seem to be prognostically significant; (ii) Silverberg grading
(combined score for architecture (1 – glandular,
2 – papillary, 3 – solid), nuclear atypia (1 – mild,
2 – moderate, 3 – strong), and mitotic count per
10 HPF (1: 0–9, 2: 10–24, 3: 25) with G1
corresponding to score 3–5, G2 6 and 7, G3
8 and 9); (iii) growth pattern-based grading
(G1 – expansile growth or infiltrative growth in
10% of tumor, G2 – infiltrative growth in >0%
of tumor); (iv) binary nuclear grading (low grade,
high grade). The current recommendation of the
International Collaboration on Cancer Reporting
(ICCR) is to use the Silverberg grading. However,
the growth-based grading seems, according to
limited literature data, to be clinically more significant and the percentage of infiltrative invasion
should also be reported.
Immunophenotype
Primary ovarian MC has an immunohistochemical profile which may show a significant overlap
with other tumors, especially from the GIT.
Despite this limitation, immunohistochemistry
plays an important role in the differential diagnosis between primary and metastatic mucinous
ovarian tumors. The summary of immunohistochemical findings in primary ovarian mucinous
tumors and metastases from the GIT is provided
in Table 1 (Dundr et al., 2021; McCluggage,
2012).
The histogenesis of primary mucinous ovarian
tumors is, to some extent, reflected in the immunohistochemical profile of the tumor. It may be
different in tumors arising from mucinous metaplasia (Walthard’s nests or in Brenner’s tumor)
and in tumors arising in connection with teratoma,
which represent a heterogeneous group. Some of
the teratoma-associated tumors mimic intestinal
Mucinous Tumors, Pathology of the Ovary, Table 1 The results of immunohistochemical examinations with
antibodies used in the differential diagnosis between primary mucinous ovarian tumors and gastrointestinal metastases
Ovary (MC) Appendix Colorectum Pancreas Pancreatobiliary system Stomach
SATB2 8 85 75 0 0 5
CDX2 45 (25) 95 95 20 30 60 (15)
CK7 90 25 (15) 30 (5) 95 95 (80) 70
CK20 65 (40) 90 (75) 90 (75) 60 (15) 55 (20) 70 (50)
MUC1 75 (30) – 40 90 90 55
MUC2 45 (20) – 70 (25) 8 8 55
MUC5AC 75 85 90 (5) 90 75 75
MUC6 60 (15) –– 75 55 10
a
DPC4
CEA 60 (5) 100 90 (40) 80 80 70
PAX8 35 (8) 5 0 0 5 0
ER 9 7 0 0 0 0
PR 9 15 0 – 00
Ca125 5 0 10 0 50 0
The results are given as a percentage of positive cases. The values in parentheses correspond to a 3+ positivity and are
provided only in the cases in which the data were available, and where this positivity differed significantly from the overall
positivity
MC mucinous carcinoma
a
Loss of expression
10 25 20 40 40 5
Mucinous Tumors, Pathology of the Ovary 327
https://t.me/med1917
(appendicular) tumors, and these tumors probably
arise from teratoma tissue with features of lower
GIT tissue. In addition to morphology, these
tumors have an immunophenotype which is
shared with the lower GI tract. However, other
teratoma-associated tumors can have a morphology and immunophenotype more compatible with
the upper GI or pancreatobiliary tract. In contrast
to tumors of non-teratomatous origin, which typically show diffuse CK7 expression and variable
CK20 expression (Fig. 3e), teratoma-associated
tumors are more heterogeneous and incl ude CK7
negative and CK20 positive cases, the most common IHC coordinates of colorectal cancer. In
cases of a mucinous ovarian tumor showing the
morphology and immunophenotype of the lower
GIT, it is possible that the teratoma component
representing the tumor minority was not detected
in the biopsy and some authors recommend extensive examination of the material to exclude a
possible teratoma component of the tumor. Otherwise, correlation with clinical data and thorough
follow-up is needed to exclude the possibility of a
metastatic tumor. However, in the literature,
immunohistochemical studies are usually
performed regardless of the precursor, which is
often not identifiable. Therefore, in most studies
the literature data concerning the immunohistochemical profile of primary ovarian mucinous
tumors are aggregated, regardless of the exact
histogenesis of the tumor.
Primary mucinous ovarian carcinomas express
CK7 in about 90% of cases, and almost always
diffusely. CK20 expression is also relatively common in these tumors and occurs in about 65% of
cases. However, CK20 expression in usually not
diffuse. Most tumors show a co-expression of
cytokeratin 7 and cytokeratin 20 (about 67%), or
only the expression of cytokeratin 7 (about 26%).
The isolated expression of cytokeratin 20 is rare in
primary tumors (about 7%), and mostly occurs in
teratoma-associated tumors (in about 50% of
them). Among other markers, CDX2 positivity
occurs in about 50% of primary MCs. PAX8
expression has been reported in about 35% of
cases but can be relatively weak and focal.
SATB2 expression is rare, occurring in about 8%
of cases. The diffuse expression of p16 is very rare
and is reported in about 5% of primary ovarian
MC, which may be helpful in the differential
diagnosis between primary ovarian MC and
metastasis from HPV-associated cervical adenocarcinoma. Another potentially useful marker,
DPC4, is rarely deleted in primary mucinous
tumors (5–10%), which can be helpful in the
differential diagnosis of metastases of pancreatic
or pancreatobiliary origin, as in these tumors
DPC4 is deleted in approximately 50–60% of
cases (Fig. 5).
Molecular Features
Approximately 50–65% of mucinous carcinoma
carry KRAS mutations. The KRAS mutations seem
to be the first event leading to a neoplastic process,
and the subsequent TP53 mutations are considered to be the trigger leading to malignant transformation, as TP53 mutations occurred more
frequently in mucinous carcinoma (17–69%)
than mucinous borderline tumor (0–33%)
(Dundr et al., 2023a, b; Hunter et al., 2012;
Chang et al., 2016; Lee et al., 2016; Mackenzie
et al., 2015; Rechsteiner et al., 2013). Loss of
heterozygosity (LOH), homozygous deletions, or
mutations in the tumor suppressor gene
have been reported in 20–76% of cases. These
aberrations are not mutually exclusive, with
KRAS mutations and coexistence of KRAS/
CDKN2A aberrations commonly found in all
types of primary ovarian mucinous tumors.
ERBB2 amplification appears to be a relat ively
late event in the process of carcinogenesis and
occurs significantly less frequently in MBT
(5–20%) than in MC (up to 43%) (Anglesio
et al., 2013; Dundr et al., 2023a; Chang et al.,
2016; Chao et al., 2014; McAlpine et al., 2009).
Differential Diagnosis
The main differential diagnosis of primary ovarian MC includes the distinction from MBT, primary ovarian endometrioid carcinoma (EC), and
tumors of metastatic origin.
The differential diagnosis between primary
ovarian MC and EC based solely on morphologic
features can be problematic in some cases. Some
EC may have prominent (and even exclusive)
mucinous differentiation, and on the contrary,
CDKN2A
M
328 Mucinous Tumors, Pathology of the Ovary
https://t.me/med1917
Mucinous Tumors, Pathology of the Ovary,
Fig. 5 Ovarian metastasis of gastric adenocarcinoma (a).
Note the gelatinous consistency of the tumor. Ovarian
metastasis of diffuse gastric carcinoma with signet ring
some MC are mucin-poor. However, EC can show
the so-called confirmatory endometrioid features
(squamous differentiation, endometriosis, endometrioid adenofibromatous areas), as well as
areas of cribriform, microacinar, and solid growth,
which are not typical for MC. In these doubtful
cases, the immunohistochemistry can be very
helpful as the immunohistochemical profile of
EC and MC is very different. This includes the
expression of cytokeratin 20 (negative in most
EC), estrogen and progesterone receptor
(positive in most EC), and PAX8 (focally and
weakly positive in some MC, diffusely and
strongly positive in most EC).
The distinction between primary ovarian
mucinous tumors and metastatic lesions can be
difficult, especially in tumors originating in the
gastrointestinal tract (Fig. 4). The most common
source of ovarian metastases is colorectal cancer,
which accounts for approximately 32% of ovarian
metastases, followed by breast carcinoma (15%),
cells (Krukenberg tumor) (b). Metastasis of gallbladder
carcinoma with extracellular pools of mucin (c). Ovarian
metastasis of pancreatic adenocarcinoma with loss of
DPC4 expression in the tumor cells (d)
endometrial carcinoma (13%), gastric carcinoma
(9%), and appendiceal carcinoma (6%). There are
some macroscopic and microscopic features
which can be helpful and suggestive of a more
likely primary or secondary origin of the tumor.
Whereas some features are more typical for primary tumors, such as a smooth surface, areas of
MBT or mucinous cystadenoma, expansile invasion, and associated teratoma or Brenner tumor,
others are suggestive of a metastatic origin, such
as surface involvement, nodular growth, hilar
involvement, and signet ring cell component
(Dundr et al., 2021; Lee & Young, 2003;
McCluggage & Wilkinson, 2005). All features
with a possible use in the differential diagnosis
are summarized in Table 2.
However, none of the features is entirely specific for either primary or metastatic source of the
tumor. For example, the presence of signet ring
cells is strongly suggestive of metastatic origin
and its specificity for metastatic origin of the
Соседние файлы в папке Библиотека им академика М.И. Перельмана