Mesenchymal Neoplasms of the Female Genital Tract
Case 7 -
Teri Longacre, Esther Oliva and Robert Soslow
Uterine leiomyosarcoma is the most common uterine sarcoma among young women. It represents
approximately 45% of all uterine sarcomas but only 1% of all uterine malignancies. It is the malignant
counterpart of uterine leiomyoma; however, the incidence of malignant transformation of leiomyomas is
very low. There seems to be an increased incidence of leiomyosarcoma among black women, although not as
pronounced as with leiomyomas.
Most leiomyosarcomas occur in women over 40 years of age. Patients frequently present with abnormal
vaginal bleeding, pain or both. Although rapid enlargement of a myometrial tumor may suggest
leiomyosarcoma, a similar finding occurs in leiomyomas in women taking oral contraceptives and on
occasion in patients without an obvious predisposing cause. In rare patients, the presenting
manifestations are related to tumor rupture (and hemoperitoneum), extrauterine extension (present in
one-third to one-half of cases), or metastases.
These tumors are typically large solitary masses with a mean diameter of 10 cm, however, 25% of the
tumors were < 5 cm in one series. Approximately two-thirds of leiomyosarcomas are intramural,
one-fifth submucosal, and one-tenth subserosal; 5% arise in the cervix. They are almost always less
circumscribed than leiomyomas and cannot be shelled out from the adjacent myometrium. In 90% of cases,
leiomyosarcomas are either the only mass, or when associated with leiomyomas (as they often are), the
largest mass. Convincing examples of leiomyosarcoma arising in a typical leiomyoma or leiomyoma
variants, however, are rare.
Leiomyosarcomas can be divided in three main categories: a) conventional/spindle; b) epithelioid; and
c) myxoid. The distinction is important as the diagnostic criteria vary from type to type.
A) Spindle cell leiomyosarcoma
The cut surface is typically bulging, soft, fleshy and focally necrotic and hemorrhagic At low-power,
conventional leiomyosarcomas frequently show an infiltrative growth with destruction of
the surrounding myometrium. They are composed of long intersecting fascicles of spindled cells with
eosinophilic fibrillary cytoplasm and elongated blunt-ended nuclei. These tumors are frequently,
although not always, hypercellular and this feature is not considered a criterion of malignancy.
Microscopic diagnostic criteria include:
-Diffuse moderate to marked nuclear atypia
-High mitotic rate (>10 mitoses/10 HPFs; 90% have
>15 MFs/10 HPFs)
-Tumor cell necrosis, characterized by an abrupt transition from viable to
non-viable cells without an interposed zone of granulation or fibrous tissue. Preserved nuclei with
marked pleomorphism and hyperchromasia can still be seen within the necrotic areas and there is a
perivascular growth of the viable tumor cells. Tumor cell necrosis is highly characteristic of
leiomyosarcomas and its presence should be considered worrisome. This type of necrosis should be
distinguished from infarct-type necrosis that may be seen in benign or
malignant smooth muscle tumors. It is characterized by the finding of granulation tissue or fibrous or
hyalinized tissue between the necrotic and the viable tumor (depending of the age of the infarct); it is
also frequently associated with recent hemorrhage. The necrotic tissue has a mummified and homogeneous
appearance with no perivascular growth of tumor cells. There is a third type of necrosis, ulcerative
necrosis, which typically involves the ulcerated surface of a submucosal smooth muscle tumor and it is
surrounded by prominent numbers of inflammatory cells, especially neutrophils, and may be seen in benign
and malignant smooth muscle tumors.
In the experience of Bell and colleagues, any of the two of the three criteria listed above warrant a
diagnosis of leiomyosarcoma. In some cases, the distinction between early infarct-type necrosis and
tumor cell necrosis may be extremely difficult.
Rare leiomyosarcomas contain a prominent component of osteoclastic type giant
cells. In some cases, the giant cell component of the tumor resembles a benign or malignant giant
cell tumor of bone or a giant cell variant of malignant fibrous histiocytoma. Rare "xanthomatous leiomyosarcomas" which can be focally or diffusely yellow, contain
large cells with abundant cytoplasm, lipid vacuoles, and multiple or multilobulated nuclei sometimes
disposed in a wreath-like arrangement. The xanthomatous cells are disposed in solid sheets or are
intimately admixed with smooth muscle cells.
Diagnostic Criteria for Uterine Smooth Muscle Tumors (Bell Et Al.)
- MI<20 /10 HPFs, no tumor cell necrosis, no
atypia, or no more than mild cytologic atypia: LEIOMYOMA WITH INCREASED MITOTIC ACTIVITY.
- MI>20 /10 HPFs, no tumor cell necrosis, no atypia
or no more than mild cytologic atypia: LEIOMYOMA WITH INCREASED MITOTIC ACTIVITY BUT EXPERIENCE LIMITED.
- MI<10 /10 HPFs, no tumor cell necrosis, but with
focal moderate to severe cytologic atypia: ATYPICAL LEIOMYOMA WITH LIMITED EXPERIENCE.
- 0< MI<10 /10 HPFs, no tumor cell necrosis, but
with diffuse moderate to severe cytologic atypia: ATYPICAL LEIOMYOMA WITH LOW RISK OF RECURRENCE.
- MI<10/ 10 HPFs, with tumor cell necrosis and no
to mild cytologic atypia: SMOOTH MUSCLE TUMOR OF LOW MALIGNANT POTENTIAL.
- MI>10 /10 HPFs, no tumor cell necrosis, but with
diffuse moderate to severe cytologic atypia: LEIOMYOSARCOMA
- Any MI with tumor cell necrosis, with diffuse or
focal moderate to severe cytologic atypia: LEIOMYOSARCOMA.
- MI>10/10 HPFs, with tumor cell necrosis, no to
mild atypia: LEIOMYOSARCOMA.
B) Epithelioid leiomyosarcoma
On low power examination these tumors most frequently show diffuse growth, but the cells can also form
nests, cords or occasionally pseudoglandular spaces. Stromal hyalinization may be slight and focal, or
marked and diffuse, particularly in association with a plexiform pattern, and rare tumors have had a
myxoid stroma. The cytoplasm is usually eosinophilic and granular, but may be clear, and in about 25% of
the cases the entire tumor is composed of clear cells. The round or angular nucleus is typically central
but may be eccentric, occasionally resulting in a signet-ring appearance. Because of the rarity of
these tumors, criteria predictive of malignancy are less well established than for conventional
leiomyosarcomas. However, as a general rule, the finding of > 5 mitoses/10 HPFs, diffuse moderate to severe cytologic atypia or tumor cell necrosis
warrants a diagnosis of epithelioid leiomyosarcoma.
C) Myxoid leiomyosarcoma
These tumors typically have a gelatinous cut surface and often a deceptively well-circumscribed
border. On microscopic examination, they infiltrate the myometrium in irregular tongues, and in some
cases myometrial veins, a feature that may be quite striking. In contrast to conventional
leiomyosarcomas, most or all tumors are hypocellular. They are characterized by an abundant
paucicellular myxoid matrix that is weakly basophilic or eosinophilic, weakly positive with the periodic
acid-Schiff and mucicarmin, and strongly positive with alcian blue and colloidal iron. The tumor cells
may be uniformly distributed throughout the myxoid stroma or arranged in loose fascicles. They usually
exhibit only focal mild to moderate nuclear pleomorphism. Most of the tumor cells have scant cytoplasm,
oval, spindle, or stellate nuclei with small nucleoli and, with rare exceptions, very low mitotic rates.
Non-myxoid areas, which are present to a variable degree, usually exhibit greater degrees of nuclear
pleomorphism and mitotic activity and architectural and cytologic features that help establish the smooth
muscle nature of the neoplastic cells. Criteria for the diagnosis of malignancy in
myxoid smooth muscle tumors include severe cytologic atypia and tumor cell necrosis (as in conventional
leiomyosarcomas). However, in the absence of tumor cell necrosis and severe cytologic atypia the finding
of > 2mitoses/10 HPFs in a myxoid smooth muscle tumor establishes the
diagnosis of myxoid leiomyosarcoma.
In general it is important to remember that:
- Thorough sampling is recommended any time a smooth muscle tumor has an unusual gross
appearance (at least one section per centimeter in diameter).
- Experience with cervical smooth muscle tumors is very limited and that these tumors should be
treated with caution.
Leiomyosarcomas express smooth muscle markers including desmin, h-caldesmon, smooth muscle myosin, and
HDCA8. However, it is important to keep in mind that epithelioid and myxoid leiomyosarcomas may show
lesser degrees of positivity for smooth muscle markers. Leiomyosarcomas are also frequently positive for
CD10 and epithelial markers including keratin and EMA (the latter more frequent in the epithelioid
variant). Conventional leiomyosarcomas express ER, PR and AR in approximately 30 to 40% of cases. Of
note, it has been shown that leiomyosarcomas may stain for CD117 (c-kit) although c-kit mutations have
not been detected up to date.
Uterine leiomyosarcomas should be distinguished from leiomyoma variants,
commonly leiomyoma with bizarre nuclei and mitotically active leiomyoma, but they should also be
distinguished from spindle cell rhabdomyosarcomas and high-grade endometrial sarcoma.
Conventional leiomyosarcoma vs leiomyoma with bizarre nuclei
Leiomyomas with bizarre nuclei cause concern for malignancy because they display large atypical
multinucleated or mononucleated cells, karyorrhectic nuclei simulating abnormal mitotic figures,
prominent nucleoli, coarse chromatin and finally the presence of mitotic counts up to 7MFs/10HPF by the
higher mitotic count. Helpful features to establish the diagnosis of leiomyoma with bizarre nuclei
include the patchy distribution of the "atypical" cells in most cases, prominent nuclear
pseudoinclusions, and degenerative type atypia of cells with pyknotic nuclei. The mitotic count,
determined by averaging mitotic counts in a number of sets of 10 high power fields, typically ranges from
0 to 2.8 MFs/10HPFs (mean 0.8). In these cases it is very important to recognize that the areas not
containing bizarre cells show bland cytologic features.
Conventional leiomyosarcoma vs mitotically active leiomyoma
These tumors may cause concern for leiomyosarcoma because of high mitotic rates that range from 5 to
15 MFs/HPFs (or even 19 in one series). This diagnosis is only allowed in the absence of nuclear
pleomorphism (no more than mild nuclear atypia) and tumor cell necrosis. In contrast to leiomyosarcomas,
these tumors almost always occur in women of reproductive age and are typically associated with the
secretory phase of the menstrual cycle, pregnancy, or the use of exogenous hormones, consistent with the
mitogenic effect of progestins on uterine leiomyomas.
Conventional leiomyosarcoma vs rhabdomyosarcoma
The more common types of uterine rhabdomyosarcoma (pleomorphic and embryonal) do not pose problems in
the differential diagnosis with leiomyosarcoma. In the spindle cell variant the cells are predominantly
spindled with elongated nuclei mimicking a conventional leiomyosarcoma. The finding of occasional cells
with round eosinophilic cytoplasm, cytoplasmic cross striations, and positivity for skeletal muscle
markers, myoglobin, and myoD1 are helpful in this differential diagnosis.
Conventional leiomyosarcoma vs high-grade endometrial sarcoma
This is a high-grade sarcoma with no specific differentiation and thus, this should be a diagnosis of
Epithelioid leiomyosarcoma vs poorly differentiated carcinoma
Both entities share the presence of cells with abundant cytoplasm and an epithelial-like growth. Most
carcinomas, however, exhibit, at least focally, overt glandular or squamous differentiation.
Immunohistochemical or ultrastructural studies may facilitate the diagnosis. It is important to keep in
mind that epithelioid smooth muscle tumors are frequently positive for keratin and EMA, thus, the use of
a panel of antibodies rather than a single antibody is recommended.
Epithelioid leiomyosarcoma vs metastatic malignant melanoma
Metastatic malignant melanoma to the uterus is an unusual finding, but it should always be taken into
account in the differential diagnosis of a uterine epithelioid neoplasm. This diagnosis can be excluded
utilizing immunohistochemistry as they are S-100 and HMB-45 positive and lack of reactivity for smooth
Epithelioid leiomyosarcoma vs placental site trophoblastic tumor (PSTT) and epithelioid trophoblastic tumor (ETT)
Features shared by tumors derived of the intermediate trophoblast and epithelioid leiomyosarcoma
include: a) myometrial-based tumor, b) diffuse growth and cells, c) abundant eosinophilic to clear
cytoplasm. Features favoring a diagnosis of a trophoblastic tumor include a history of a recent
pregnancy, an elevated serum hCG level, an infiltrative growth pattern with tumor cells dissecting
preexisting smooth muscle bundles (PSTT), prominent vascular involvement (PSTT), fibrinoid change in
vessel walls (PSTT), well circumscribed margins (ETT), nested growth around vessels (ETT), extensive
areas of geographical necrosis (ETT), and immunoreactivity for CK18, inhibin and placental lactogen
(both) and p63 (ETT).
Epithelioid leiomyosarcoma vs uterine tumors resembling ovarian sex-cord tumor (UTROSCT)
These tumors show prominent "epithelial-like" differentiation and frequently express smooth muscle and
epithelial markers as epithelioid leiomyosarcomas. However, overall the degree of epithelial
differentiation in most UTROSCTs is more pronounced than in epithelioid leiomyosarcomas, and tubular
formation or even a retiform morphology and cells with prominently vacuolated cytoplasm can be seen.
Furthermore, some of these tumors may also express inhibin, CD99 and calretinin, the so-called "sex cord
markers.", Inhibin, at least, is always negative in smooth muscle tumors.
Epithelioid leiomyosarcoma vs "PEComa"
PEComa shares with an epithelioid leiomyosarcoma the following features: a) cells disposed in sheets
or small solid nests or cords; b) cells with abundant clear or eosinophilic cytoplasm; c) expression of
smooth muscle markers. However, "PEComas" are characteristically positive for HMB-45, Melan A and
othermelanocytic markers while smooth muscle tumors for the most part only
rarely express these markers (except in two recent studies where these markers show high frequency of
positivity for these markers). Furthermore PEComa is frequently associated with tuberous sclerosis and
lymphangiomyomatosis, while such association is not seen in smooth muscle tumors. The relationship
between epithelioid leiomyosarcoma and uterine PEComa has yet to be clarified.
Epithelioid leiomyosarcoma vs alveolar soft part sarcoma
Alveolar soft part sarcoma of the female genital tract is uncommon and often misdiagnosed as a
carcinoma or an epithelioid smooth muscle tumor. Solid variants of the alveolar pattern simulate the
nested pattern of epithelioid leiomyosarcoma and both tumors contain cells with abundant pale cytoplasm.
However, the typical alveolar growth pattern (with central spaces and cells falling into the spaces),
fibrovascular septae, PAS-positive diastase resistant granules and crystals seen in alveolar soft part
sarcoma are lacking in epithelioid leiomyosarcoma. Furthermore, the latter is often associated with
spindle cell areas to a variable extent, a feature that is not seen in alveolar soft part sarcoma.
Immunohistochemical stains are of no help as both tumors are positive for smooth muscle markers except
for TFE3. Alveolar soft part sarcomas are characterized by the t(x;17)(p11;q25) with fusion of TFE3
transcription factor gene on Xp11 to a novel gene on 17q25. Thus, nuclear TFE3 staining can be used as a
marker of these tumors.
Myxoid leiomyosarcoma vs myxoid leiomyoma
In contrast to myxoid leiomyosarcoma, myxoid leiomyomas are usually well circumscribed on gross and
microscopic examination, the cytologic features are bland and mitotic figures are extremely rare. A
mitotic index of <2 MFs /10 HPFs favors the diagnosis of myxoid leiomyoma. The distinction may be
difficult in curettage specimens and the pathologist should be very cautious in these cases. It is
important to be aware that a benign smooth muscle tumor may be only focally myxoid. Mistaking non-myxoid
portions of the leiomyoma for myometrium may lead to the erroneous conclusion that myxoid portions of the
tumor have invaded myometrium, resulting in a diagnosis of myxoid leiomyosarcoma.
Myxoid leiomyosarcoma vs intravenous leiomyomatosis with myxoid change
Both entities share an intravascular growth pattern which can be quite prominent in leiomyosarcoma.
However, the finding of any degree of cytologic atypia, mitotic activity as well as extravascular tumor
will favor the diagnosis of leiomyosarcoma.
Myxoid leiomyosarcoma vs leiomyoma with prominent hydropic change
In some cases, the edematous background may be confused with a myxoid matrix. This is particularly
problematic when the hydropic change extends beyond the confines of the leiomyoma, which could lead to
the impression of an infiltrative tumor. The distinction is crucial and can be achieved using alcian
blue or colloidal iron, typically negative in leiomyomas with hydropic change.
Myxoid leiomyosarcoma vs myxoid endometrial stromal sarcoma
Some endometrial stromal sarcomas show prominent myxoid and/or fibrous background and may be
misdiagnosed as myxoid leiomyosarcoma as the latter is more common. Helpful features to establish the
diagnosis of endometrial stromal sarcoma include; a) the typical tongue-like pattern of infiltration, b)
absence of fascicular growth, c) small vessels, and, d) in most cases, areas of conventional endometrial
stromal neoplasia. These tumors may also cause problems when they metastasize, particularly to the lung,
where a myxoid/fibrous appearance can predominate. It is important to notice that in some instances this
appearance will be encountered in metastatic sites, but not in the primary tumor. Immunohistochemistry
may be helpful using a panel that includes CD10, desmin and caldesmon.
Treatment and Prognosis
The treatment of choice for leiomyosarcomas is total abdominal hysterectomy and debulking of tumor if
present outside the uterus, while removal of the ovaries and lymph node dissection remains
controversial. Leiomyosarcomas have an overall poor prognosis. The 5-survival rate ranges from 12% to
40% for all stages while increases to 50-70% for tumors confined to the uterus. Up to 70% of patients
with leiomyosarcomas confined to the uterus and nearly all with extrauterine disease at initial diagnosis
will eventually recur with a median time to recurrence of 8 to 16 months. Myxoid and epithelioid
leiomyosarcomas are aggressive tumors but with a postoperative interval to recurrence or metastases as
long as 10 years in contrast to the conventional subtype. Leiomyosarcomas follow a hematogenous spread,
commonly involving lung and liver. Hormonal status does not influence overall survival when corrected
for stage, however, some patients may respond to hormonal treatment. In general, there is a poor
correlation between survival and clinical or pathologic parameters. However, in a study of 208 uterine
leiomyosarcomas, tumor grade and stage emerged as the most accurate predictive parameters. Other
parameters including patient age >51 years, tumor size > 5cm and menopausal status also seemed to
be associated with reduced overall survival at least by univariate analysis. p53, DNA ploidy, Bcl-2 may
have a role in predicting outcome in leiomyosarcomas but it is not clear that these factors act
independently of stage. In fact, stage is still the most powerful prognostic factor
- Clement PB. Pure mesenchymal tumors. In Tumors and tumor-like
conditions of the uterine corpus and cervix. PB Clement and RH Young, Eds. Churchill Livingstone
- Bell SW, Kempson RL, Hendrickson MR. Problematic uterine smooth muscle neoplasms. A
clinicopathologic study of 213 cases. Am J Surg Pathol 18:535-558, 1994.
- Longrace TA, Hendrickson MR, Kempson RL. Predicting clinical outcome for uterine smooth muscle
neoplasms with a reasonable degree of certainty. Adv in Anat Pathol 4:95-104, 1997.
- Clement PB, Young RH. Mesenchymal and mixed epithelial-mesenchymal
tumors of the uterine corpus and cervix. In: Atlas of Gynecologic surgical pathology.
Philadelphia: WB Saunders 2000.pp 177-210.
- Clement PB. The pathology of uterine smooth muscle tumors and mixed endometrial stromal and
smooth muscle tumors: A selected review with emphasis on recent advances. Int J Gynecol Pathol
- Kempson RL, Hendrickson MR. Smooth muscle, endometrial stromal, and mixed mullerian tumors of the
uterus. Mod Pathol 13:328-342, 2000.
- Wilkinson N, Rollason TP. Recent advances in the pathology of smooth muscle tumours of the
uterus. Histopathology 39:331-341, 2001.
- Benda JA. Pathology of smooth muscle tumors of the uterine corpus. Clin Obstet Gynecol
- Oliva E, Clement PB, Young RY. Mesenchymal tumors of the uterus: selected topics emphasizing
diagnostic pitfalls. Current Diag Pathol 2002;8:268-282.
- Hart WR, Billman JK, Jr. A reassessment of uterine neoplasms originally diagnosed as
leiomyosarcomas. Cancer 1978;41:1902-1910.
- Evans HL, Chawla SP, Simpson C, Finn KP. Smooth muscle neoplasms of the uterus
other than ordinary leiomyoma. A study of 46 cases, with emphasis on diagnostic criteria and prognostic
factors. Cancer 1988;62:2239-2247.
- Schwartz LB, Diamond MP, Schwartz PE. Leiomyosarcomas: clinical presentation.
Am J Obstet Gynecol 1993;168:180-183.
- Major FJ, Blessing JA, Silverberg SG, et al. Prognostic factors in early-stage uterine sarcoma.
A Gynecologic Oncology Group study. Cancer 1993;71:1702-1709.
- Barter JF, Smith EB, Szpak CA, Hinshaw W, Clarke-Pearson DL, Creasman WT. Leiomyosarcoma of the
uterus: clinicopathologic study of 21 cases. Gynecol Oncol 1985;21:220-227.
- Larson B, Silfversward C, Nilsson B, Pettersson F. Prognostic factors in uterine leiomyosarcoma.
A clinical and histopathological study of 143 cases. The Radiumhemmet series 1936-1981. Acta Oncol
- Jones MW, Norris HJ. Clinicopathologic study of 28 uterine leiomyosarcomas with metastasis. Int
J Gynecol Pathol 1995;14:243-249.
- Bodner K, Bodner-Adler B, Kimberger O, Czerwenka K, Leodolter S, Mayerhofer K. Evaluating
prognostic parameters in women with uterine leiomyosarcoma. A clinicopathologic study. J Reprod Med
- Mayerhofer K, Obermair A, Windbichler G, Petru E, Kaider A, Hefler L, Czerwenka K, Leodolter S,
Kainz C. Gynecol Oncol 74:196-201, 1999.
- Zhai YL, Kobayashi Y, Mori A, Orii A, Nikaido T, Konishi I, Fujii S. Expression of steroid
receptors, Ki-67, and p53 in uterine leiomyosarcomas. Int J Gynecol Pathol 18:20-8, 1999.
- Rao UN, Finkelstein SD, Jones MW. Comparative immunohistochemical and molecular analysis of
uterine and extrauterine leiomyosarcomas. Mod Pathol 12:1001-9, 1999.
- Giuntoli RL, Metzinger DS, DiMarco CS, Cha SS, Sloan JA, Henney GL, Gostout BS. Retrospective
review of 208 patients with leiomyosarcoma of the uterus:prognostic indicators, surgical management, and
adjuvant therapy. Gynecol Oncol 2003;89:460-469.
- Hu J, Khanna V, Jones M, Surti U. Genomic alterations in uterine leiomyosarcomas: potential
markers for clinical diagnosis and prognosis. Genes, Chromosomes Cancer 2001;31:117-124.
- Levy B, Mukherjee T, Hirschhorn K. Molecular cytogenetic analysis of uterine leiomyoma and
leiomyosarcoma by comparative genomic hybridization. Cancer Genet Cytogenet 2000:121:1-8
- Leiato MM, Sonoda Y, Brennan MF, Barakat RR, Chi DS. Incidence of lymph node metastases in
leiomyosarcoma of the uterus. Gynecol Oncol 2003:91:209-212.
- Dinh TA, Oliva E, Fuller AF, Lee H, Goodman A. The treatment of uterine leiomyosarcoma. Results
from a 10-year experience (1990-1999) at the Massachusetts General Hospital. Gynecol Oncol
- O'Connor DM, Norris HJ. Mitotically active leiomyomas of the uterus. Hum Pathol 21:223-227,
- Perrone T, Dehner LP. Prognostically favorable "mitotically active" smooth muscle tumors of the
uterus. A clinicopathologic study of 10 cases. Am J Surg Pathol 12:1-8,1988.
- Prayson RA, Hart WR. Mitotically active leiomyomas of the uterus. Am J Clin Pathol
- Downes KA, Hart WR. Bizarre leiomyomas of the uterus : A comprehensive pathologic study of 24
cases with long-term follow-up. Am J Surg Pathol 21:1261-70,1997.
- Downes KA, Hart WR. Bizarre uterine leiomyomas: Ki-67 activity and DNA ploidy. Abstract. Mod
Pathol 12: 116A, 1999.
- Clement PB, Young RH, Scully RE. Diffuse, perinodular, and other patterns of hydropic
degeneration within and adjacent to uterine leiomyomas. Problems in differential diagnosis. Am J Surg
Pathol 16:26-32, 1992.
- Ordi J, Stamatakos MD, Tavassoli FA. Pure pleomorphic rhabdomyosarcomas of the uterus. Int J
- Kurman RJ, Norris HJ. Mesenchymal tumors of the uterus. VI. Epithelioid smooth muscle tumors
including leiomyoblastoma and clear-cell leiomyoma. A clinical and pathological analysis of 26 cases.
- Prayson RA, Goldblum JR, Hart WR. Epithelioid smooth-muscle tumors of the uterus: A
clinicopathologic study of 18 patients. Am J Surg Pathol 21:383-91,1997.
- Oliva E, Nielsen PG, Clement PB, Young RY, Scully RE. Epithelioid smooth muscle tumors of the
uterus. A clinicopathologic analysis of 80 cases. Abstract. Mod Pathol 10:107A, 1997.
- Atkins K, Bell S, Kempson R, Hendrickson M. Epithelioid smooth muscle
of the uterus. Modern Pathol2001; 14:132A.
- Kyriazis AP, Kyriazis AA. Uterine leiomyoblastoma (epithelioid leiomyoma) neoplasm of low-grade
malignancy. A histopathologic study. Arch Pathol Lab Med 1992;116:1189-1191.
- Aida Y, Tadokoro M, Takeuchi E, et al. Myxoid variant of epithelioid
leiomyosarcoma of the uterus. Acta Pathol Jpn 1991;41:778-783.
- Silva EG, Tornos C, Ordonez NG, Morris M. Uterine leiomyosarcoma with clear cell areas. Int J
Gynecol Pathol 1995;14:174-178.
- Ito H, Sasaki N, Miyagawa K, Tahara E. Bizarre leiomyoblastoma of the cervix uteri.
Immunohistochemical and ultrastructural study. Acta Pathol Jpn 1986;36:1737-1745.
- Seidman JD, Yetter RA, Papadimitriou JC. Epithelioid component of uterine leiomyosarcoma
simulating metastatic carcinoma. Arch Pathol Lab Med 1992;116:287-290.
- Silva EG, Tornos C, Ordonez NG, Morris M. Uterine leiomyosarcoma with clear cell areas. Int J
Gynecol Pathol 1995;14:174-178.
- Silva EG . Deavers MT, Bokurda DC, Malpica A Uterine leiomyosarcoma with clear cell areas.
Reactivity with HMB-45 and the concept of PEComa. 2004;28:44-49.
- Simpson KW, Albores-Saavedra J. HMB-45 Reactivity in Conventional Uterine Leiomyosarcomas. Am J
Surg Pathol 2007;31:95-8.
- Oliva E, Wang WL, Branton P, et al. Expression of melanocytic ("PEComa") markers in smooth
muscle tumors of the uterus: an immunohistochemical analysis of 86 cases. Mod Pathol. 2006;86:191A
- Shih IM, Kurman RJ. Epithelioid trophoblastic tumor: a neoplasm distinct from choriocarcinoma
and placental site trophoblastic tumor simulating carcinoma. Am J Surg
- Young RH, Scully RE. Placental-site trophoblastic tumor: current status. Clin Obstet Gynecol 1984;27:248-257.
- Vang R, Kempson RL. Perivascular epithelioid cell tumor (PEComa) of the uterus: A subset of
HMB-45-positive epithelioid mesenchymal neoplasms with an uncertain relationship to pure smooth muscle
tumors. Am J Surg Pathol 2002; 26:1-13.
- Bosincu L, Rocca P, Martignoni G, Nogales, FF, Longa L, Maccioni A, Massarelli G. Perivascular
epithelioid cell (PEC) tumors of the uterus: a clinicopathologic study of two cases with aggressive
features. Mod Pathol 2005;18:1336-1342.
- Folpe A, Mentzel T, Lehr HA, Fisher C, Balzer BL, Weiss SW. Perivascular epithelioid cell
neoplasms of soft tissue and gynecologic origin: a clinicopathologic study of 26 cases and review of the
literature. Am J Surg Pathol. 2005;29:1558-75.
- Hornick JL, Fletcher CD. PEComa: what do we know so far? Histopathology. 2006;48:75-82. Young
RH, Scully RE. Oxyphilic tumors of the female and male genital tracts. Semin Diagn Pathol
- Iwata J, Fletcher CD. Immunohistochemical detection of cytokeratin and epithelial membrane
antigen in leiomyosarcoma: a systematic study of 100 cases. Pathol Int. 2000;50:7-14.
- Guillou L, Lamoureux E, Masse S, Costa J. Alveolar soft-part sarcoma of the uterine corpus:
histological, immunocytochemical and ultrastructural study of a case. Virchows
Arch A Pathol Anat Histopathol. 1991;418:467-471.
- Ladanyi M, Antonescu CR, Drobnjak M, et al. The precrystalline cytoplasmic granules of alveolar
soft part sarcoma contain monocarboxylate transporter 1 and CD147. Am J Pathol.
- Morimitsu Y, Tanaka H, Iwanaga S, Kojiro M. Alveolar soft part sarcoma of the uterine cervix.
Acta Pathol Jpn. 1993;43:204-208.
- Nielsen GP, Oliva E, Young RH, Rosenberg AE, Dickersin GR, Scully RE. Alveolar soft-part sarcoma
of the female genital tract: a report of nine cases and review of the literature. Int J Gynecol Pathol. 1995;14:283-292.
- Roma AA, Yang B, Senior ME, Goldblum JR. TFE3 immunoreactivity in alveolar soft part sarcoma of
the uterine cervix: case report. Int J Gynecol Pathol. 2005;24:131-135.
- Sahin AA, Silva EG, Ordonez NG. Alveolar soft part sarcoma of the uterine cervix. Mod Pathol. 1989;2:676-680.
- Atkins K, Bell S, Kempson M, Hendrickson M. Myxoid smooth muscle tumors of the uterus. Modern
- King ME, Dickersin GR, Scully RE. Myxoid leiomyosarcoma of the uterus. A report of six cases.
Am J Surg Pathol 1982;6:589-598.
- Chen KT. Myxoid leiomyosarcoma of the uterus. Int J Gynecol Pathol 1984; 3:389-392. -
- Pounder DJ, Iyer PV. Uterine leiomyosarcoma with myxoid stroma. Arch Pathol
Lab Med 1985;109:762-764.
- Salm R, Evans DJ. Myxoid leiomyosarcoma. Histopathology
- Peacock G, Archer S. Myxoid leiomyosarcoma of the uterus. Case report and
review of the literature. Am J Obstet Gynecol 1989;160:1515-1519.
- Schneider D, Halperin R, Segal M, Maymon R, Bukovsky I. Myxoid leiomyosarcoma of the uterus with
unusual malignant histologic pattern--a case report. Gynecol Oncol 1995;59:156-158.
- Oliva E, Clement PB, Young RH, Scully RE. Myxoid and fibrous endometrial stromal tumors of the
uterus: A report of ten cases. Int J Gynecol Pathol 18:310-319, 1999.
- Yilmaz A, Rush DS, Soslow RA. Endometrial stromal sarcomas with unusual histologic features. A
report of 24 primary and metastatic tumors emphasizing fibroblastic and smooth muscle differentiation.
Am J Surg Pathol 2002;26:1142-1150.