Uterus
Stromal tumors
Uterine tumors resembling ovarian sex cord tumors

Author: Laura Ardighieri, M.D. (see Authors page)
Editorial Board Review: Ayse Ayhan, M.D., Ph.D.

Revised: 10 March 2017, last major update March 2017

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed search: uterine tumors resembling ovarian sex cord tumors

Cite this page: Uterine tumors resembling ovarian sex cord tumors. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/uterusUTROSCT.html. Accessed November 20th, 2017.
Definition / general
  • Rare neoplasms that resemble ovarian sex cord tumors, without a component of recognizable endometrial stroma (IARC: WHO Classification of Tumors of the Female Reproductive Organs, 4th Edition, 2014)
  • Accounts for less than 0.5% of all uterine malignancies and 10% - 15% of mesenchymal uterine malignancies (Crum et al.: High Yield Pathology - Gynecologic and Obstetric Pathology, 2016)
  • Etiology uncertain and most have benign behavior without infiltrative properties
  • 1945: Morehead and Bowman first described a case of a uterine neoplasm resembling a granulosa cell tumor
  • 1976: Clement and Scully clarified the concept of sex cord differentiation of uterine tumors and categorized into two groups:
    • Group I is endometrial stromal tumors with foci of sex cord differentiation (ETSCLE) < 50% (associated with recurrences and metastases)
    • Group II composed predominantly or exclusively by sex cord-like elements; this latest group continues to be classified as UTROSCTs
  • Miscellaneous category in WHO classification
Essential features
  • Rare uterine tumor of uncertain histogenesis; morphologically shows overlap with ovarian sex cord tumors, affecting perimenopausal or menopausal women (mean age 51):
  • Differential diagnosis crucial; different behavior
  • Present mostly as intramural, less frequently submucosal or subserosal or polypoid / intracavitary masses
  • Organized in sex cord structures (sheets, cord, nests, trabeculae, tubules) composed of epithelioid-looking cells with scant / abundant eosinophilic / clear cytoplasm and bland nuclei with minimal atypia and rare mitoses
  • Coexpression of epithelial (KL1, CK AE1 / AE3, CAM5.2, EMA), smooth muscle (smooth muscle actin, desmin, h-caldesmon, smooth muscle myosin heavy chain, histone deacetylase-8), sex cord markers (WT1, calretinin, inhibin, CD99, MelanA, CD56, FOXL2, SF1) and hormone receptors (ER, PR, AR)
  • Absence of JAZF1 / SUZ12 fusion (JAZF1-JJAZ1) and PFH1 gene rearrangements distinguish these neoplasms from endometrial stromal tumors
  • Treated by surgical removal, based on age / parity of the patients (total hysterectomy with bilateral adnexectomy or conservative surgery with hysterectomy / mass resection)
  • Benign behavior; however, low rates of recurrence (5%) have been reported and rarely development of metastases can occur
ICD-10 coding
  • 8590/1
Epidemiology
  • Perimenopausal or menopausal women (22 - 84 years); mean age is 51
  • < 1% of uterine mesenchymal tumors
Sites
Etiology
  • Tumors of uncertain histogenesis (miscellaneous category in latest WHO classification)
  • Postulated theories include (Int J Gynecol Pathol 2016;35:301):
    • Derivation from ovarian sex cord cells which have been displaced during embryogenesis
    • Derivation from uncommitted mesenchymal stem cells
    • Overgrowth of sex cord elements within endometrial stromal neoplasm or adenosarcoma (however please notice that these tumors do not have the cytogenetic abnormalities found in stromal neoplasms)
Clinical features
Diagnosis
  • Based on histomorphologic features including a predominant pattern of the cords, nests and trabeculae resembling sex cord tumors of the ovary and immunophenotype, characterized by coexpression of epithelial, smooth muscle, sex cord markers and steroid receptors
  • Imaging studies are not diagnostic; histopathology is the gold standard (Arch Pathol Lab Med 2013;137:1832)
Radiology description
  • They can be diagnosed with US, CT and MRI
  • No specific image findings: at transvaginal pelvic ultrasound they may be seen in an normal or enlarged uterus and may appear as myometrial masses, with myomatous features or as masses protruding in the endometrial cavity suggesting a polypoid lesion
Prognostic factors
Case reports
Treatment
Gross description
  • Intramural / submucosal / subserosal nodules or polypoid tumors growing in the endometrial cavity
  • Solid, round, well circumscribed masses
  • Average 6 cm; ranging from 2 to 24 cm
  • Yellow, tan, grayish white surface; firm to soft to rubbery consistency
  • Cut surface grayish yellow to white
  • Rarely predominantly cystic
  • Hemorrhage can be seen; necrosis unusual
Gross images

Images hosted on PathOut server:

Contributed by Ayse Ayhan, M.D., Ph.D.:

44 year old patient, fundus posterior 6 cm intramural neoplasm
Seirei Mikatahara Hospital, Hamamatsu, Japan

Microscopic (histologic) description
  • Usually well circumscribed but unencapsulated; may have a pseudoinfiltrative appearance due to incorporated smooth muscle bundles; true myometrial invasion rare
  • Organized in sheets, cords, nests, trabeculae, hollow or solid tubules with repetitive pattern of cordlike / tubular growth; more rarely has retiform or glomeruloid appearance or papillae and solid pattern predominance
  • Neoplastic cells are small, round to ovoid with monotonous nuclei, inconspicuous nucleoli, mild nuclear hyperchromasia, rare nuclear grooves
  • Call-Exner-like bodies may be rarely present
  • Scant intervening stroma (hyalinised, fibroblastic or edematous)
    • In some tumors endometrial stromal-type cells or benign appearing smooth muscle may be present; rare findings are a sparse lymphocytic inīŦltrate accompanied by foamy histiocytes, a few multinucleated giant cells, hemosiderin deposition or cholesterol crystals
  • Occasionally vascular invasion, heterologous elements and necrosis
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Ayse Ayhan, M.D., Ph.D.:

Images demonstrate well circumscribed but unencapsulated neoplasm organized in sheets, cords, nests, trabeculae or tubules. Neoplastic cells have round to ovoid monotonous nuclei, inconspicuous nucleoli, mild nuclear hyperchromasia, rare nuclear grooves and almost no mitoses. Notice that sex cord and epithelial markers are positively stained.



Images hosted on other servers:

Various images


Tumor cells resemble granulosa cells

Various images

Cytology description
  • Cells resembling epithelial cells, with scant cytoplasm or abundant eosinophilic / clear (including vacuolated) / foamy cytoplasm, reminiscent of Sertoli cell or granulosa cell tumors
  • Can show rhabdoid features (J Clin Pathol 2007;60:1148) with abundant eosinophilic cytoplasm and eccentric nuclei
  • Minimal atypia; rare mitoses (ranging from < 1 to 5 / 10 high power fields)
  • Ovoid and small nuclei with irregular contours (sometimes grooved)
  • Finely distributed chromatin with small to indistinct nucleoli
  • Leydig-like cells may be present
Positive stains
Electron microscopy description
  • Cell junctions, desmosome-like junctions, tonofilaments, lumina formation, microvilli (indicative of epithelial differentiation)
  • Sex cord like features (nuclear indentation, abundant intracellular filaments, endoplasmic reticulum [granulosa cells], intracytoplasmic lipid droplets
  • No dense bodies, subplasmalemmal densities or pinocytotic vesicles (indicating no smooth muscle differentiation)
  • Reference: Ultrastruct Pathol 2010;34:16
Molecular / cytogenetics description
Differential diagnosis