Uterus
Stromal tumors
Müllerian adenosarcoma

Author: Özlem Isiksacan Özen, M.D.
Editor: Ayse Ayhan, M.D., Ph.D.
Editorial Board Member Review: Carlos Parra-Herran, M.D.
Editor-in-Chief Review: Debra Zynger, M.D.

Revised: 15 October 2018, last major update March 2018

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Uterus stromal tumors adenosarcoma

Cite this page: Özen, Ö. Müllerian adenosarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/uterusadenosarcoma.html. Accessed October 17th, 2018.
Definition / general
Essential features
  • Mixed tumor with a neoplastic malignant mesenchymal component and an accompanying nonneoplastic (benign) epithelial component, as demonstrated in recent molecular studies (J Pathol 2016;238:381)
Terminology
ICD-10 coding
Epidemiology
Sites
Etiology
Clinical features
Diagnosis
  • Obtain a sufficient endometrial biopsy (pipelle or D&C)
  • Apply routine histopathologic criteria; immunohistochemistry has a limited role
Prognostic factors
Case reports
Treatment
Clinical images

Images hosted on other servers:
Missing Image

Mass protruding through cervix

Gross description
  • Usually forms polypoid masses ranging from 1 - 20 cm (mean 5 - 6.5 cm)
  • Typically fills the endometrial cavity and may project into the endocervical canal
  • Rarely mural and serosal
  • A cauliflower-like appearance may be seen
  • Cut surface is solid, white to tan in color with small cysts containing watery or mucoid fluid
  • Soft and fleshy with areas of hemorrhage or necrosis if sarcomatous overgrowth or high grade sarcoma is present
Gross images

Images hosted on PathOut server:

Image contributed by Aysha Mubeen, M.D.

Case of the Week #451



Images hosted on other servers:

Cut specimen of uterus and tumor

Endometrial polyp

Hysterectomy specimen

Microscopic (histologic) description
  • Low power reveals a biphasic tumor with intimally admixed glands and prominent stroma throughout
  • Morphologic features diagnostic of adenosarcoma are:
    • Intraglandular growth with projections narrowing the glandular lumens, imparting a leaf-like (phyllodes-like) architecture
    • Periglandular stromal condensation (cuffing)
    • Rigid cystic dilation
    • Mitotic activity ≥ 2 mitoses / 10 HPFs
    • Stromal cytologic atypia
      • Low grade adenosarcomas have monotonous stromal nuclei with mild to moderate atypia (similar to that seen in low grade endometrial stromal sarcoma)
      • High grade adenosarcomas have pleomorphic, markedly atypical nuclei, noticeable at low power magnification and ≥ 2x the size of an endothelial cell nucleus (Am J Surg Pathol 2017;41:1513)
      • They are usually associated with sarcomatous overgrowth and heterologous (rhabdomyosarcoma) differentiation
  • At least 2 of these features must be present diffusely throughout the tumor in order to make the diagnosis of adenosarcoma
  • Epithelium of the glands is usually endometrioid but often shows mucinous, squamous or tubal metaplasia and may show mild to moderate atypia
  • Stroma may show hyalinization, elastosis, edema or myxoid change
  • Sarcomatous overgrowth: presence of sarcoma (without any epithelial component) in > 25% of the tumor, most frequently homologous high grade sarcoma, associated with deeper myometrial involvement and lymphovascular invasion
  • Heterologous elements, most commonly rhabdomyosarcoma, may be present, particularly in the setting of sarcomatous overgrowth and high grade morphology
  • Other types of heterologous differentiation, such as immature cartilage, sex cord-like differentiation or smooth muscle metaplasia may be present
Microscopic (histologic) images

Images hosted on PathOut server:

Images contributed by Ayse Ayhan, M.D., Ph.D.
Missing Image

Biphasic tumor

Missing Image Missing Image Missing Image Missing Image

Periglandular cuff


Missing Image Missing Image Missing Image

Intraglandular papillae

Missing Image

Stromal mitoses

Missing Image

Squamous metaplasia


Missing Image Missing Image Missing Image

Sarcomatous overgrowth

Missing Image

Heterologous elements

Cytology images

Images hosted on other servers:
Missing Image

Denuded malignant cells with variable sizes

Missing Image

Dense clusters of polymorphic tumor cells

Missing Image

Long oval, hyperchromatic nuclei with 1+ nucleoli (Pap)

Missing Image

Partly denuded tumor cells with fragile cytoplasm

Missing Image

Tumor cells have variable sizes

Positive stains
Negative stains
Molecular / cytogenetics description
Differential diagnosis
  • Endometrial polyp: most adenosarcomas are polypoid, and can be mistaken for an endometrial polyp
  • Likewise, some endometrial polyps may display features suggestive of adenosarcoma
    • Endometrial polyps are characterized by uniformly increased cellularity of the stroma lacking periglandular cuffing, cytologic atypia or mitotic activity
    • Polyps with focal atypical features (leaf-like growth, periglandular condensation, atypia, mitoses) have an indolent outcome, and are referred currently as polyps with unusual features (Am J Surg Pathol 2015;39:116)
    • Diagnosis of adenosarcoma requires the presence of diagnostic characteristics diffusely throughout the tumor
  • Adenofibroma: an exceedingly rare biphasic tumor that should be diagnosed only in a well sampled tumor removed totally
    • Diffusely paucicellular stroma with no periglandular cuffing, no stromal atypia and absent or rare mitotic figures < 2 MF/10 HPF
  • Adenomyoma: grossly well circumscribed and the stromal component is made of smooth muscle cells that form fascicles identical to that of a leiomyoma
  • Atypical polypoid adenomyoma: stroma is fibromyomatous and glands have squamous metaplasia
  • Benign endometrial polyp: characterized by uniformly increased cellularity of the stroma lacking periglandular cuffing, cytologic atypia or mitotic activity
  • Carcinosarcoma: glandular component is frankly carcinomatous and high grade
    • Phenomenon of carcinoma arising in an adenosarcoma has been described
    • In these cases the carcinomatous component is localized, and the benign glandular component of adenosarcoma can be appreciated elsewhere
    • Moreover, the carcinoma is usually low grade endometrioid, unlike carcinosarcoma (Mod Pathol 2018;31:418)
  • Embryonal rhabdomyosarcoma: most commonly occurs in the cervix of younger women and girls (mean 18 years)
    • May contain entrapped glands which are surrounded by cuffs of tumor cells, resulting in a cambium layer
    • Entrapped glands are confined to the surface and leaf-like pattern typical of adenosarcoma is absent
    • Malignant stroma away from the cambium layer is hypocellular, edematous or myxoid alternating with small blue aggregates of neoplastic cells
  • Endometrial stromal sarcoma (when glandular elements or entrapped benign endometrial glands are present):
    • Glands in endometrial stromal tumors are usually scant and towards the periphery of the tumor and lack the periglandular stromal condensation and uniform distribution throughout the tumor seen in adenosarcoma
    • Neoplastic stroma permeates the myometrium with a tongue-like pattern in contrast to the destructive infiltration seen in adenosarcoma
    • Immunohistochemistry is not helpful as it shows an overlapping profile
  • Polypoid endometriosis: composed of endometrial stroma and endometrial type glands that may be cystically dilated; it lacks the typical periglandular cuffs, intraglandular stromal papillae or stromal cytologic atypia
Board review question #1
    Adenosarcoma of the female genital tract:

  1. Differs from adenofibroma by showing marked cellularity (including periglandular cuffs), any degree of stromal cell atypia and ≥ 2 mitotic figures per 10 high powered fields.
  2. Is associated with a good outcome even if myometrial invasion and sarcomatous overgrowth are present.
  3. Is classified as an "adenosarcoma with sarcomatous overgrowth” if a high grade sarcoma is seen in > 10% of the tumor.
  4. Is composed of glands with severe cytological atypia and a cellular low grade malignant stroma.
  5. Never shows any heterologous component while almost half of carcinosarcomas show this feature.
Board review answer #1
A. Differs from adenofibroma by showing marked cellularity (including periglandular cuffs), any degree of stromal cell atypia and ≥ 2 mitotic figures per 10 high powered fields. Adenosarcoma is a biphasic tumor composed of benign appearing epithelium and a cellular low grade malignant stroma. The main differential diagnosis includes adenofibroma and it differs from adenofibroma by showing marked cellularity (including periglandular cuffs), any degree of stromal cell atypia and ≥ 2 mitotic figures per 10 high powered fields. The tumor is classified as an adenosarcoma with sarcomatous overgrowth when at least 25% of the tumor is composed of pure sarcoma. Adenosarcoma is frequently associated with a good outcome if confined to the endometrium. Otherwise deep myometrial invasion, high grade cytomorphology and sarcomatous overgrowth predict a poor prognosis. Heterologous elements, most commonly rhabdomyosarcoma, may also be present especially in adenosarcoma with sarcomatous overgrowth.