Stromal tumors

Author: Sanjay Logani, M.D. (see Authors page)

Revised: 26 January 2017, last major update June 2010

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

PubMed search: uterine adenosarcoma

Cite this page: Adenosarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/uterusadenosarcoma.html. Accessed January 18th, 2018.
Definition / general
  • Also called müllerian adenosarcoma
  • Usually uterus or cervix, also elsewhere in gynecologic tract
  • Rare cases reported involving the intestine
  • Rosai considers these tumors to be a variant of endometrial stromal sarcoma with the capacity to form glands, including sex cord-like differentiation
Clinical features
Prognostic factors
  • Poor prognostic factors: high grade sarcomatous overgrowth, myometrial invasion or high grade tumor
Case reports
  • Hysterectomy is usually curative
  • May recur in pelvis or vagina; rarely metastasizes
Gross description
  • Bulky, polypoid and multicystic neoplasm arising from endometrium and filling endometrial cavity
  • May be fleshy
  • Mean 6 cm, but up to 20 cm
  • Less hemorrhage and necrosis than MMMT
Gross images

Images hosted on PathOut server:

Large polypoid mass fills entire endometrial cavity (fig 1E)

Microscopic (histologic) description
  • Epithelial and stromal elements with stromal hypercellularity
  • Epithelial component appears benign; glands are usually large and dilated with periglandular stromal cuffing, 80% have cambium layer (stromal condensation) beneath surface epithelium and adjacent to glands (most characteristic histologic feature); mitotic activity and cytologic atypia are more common in this zone
  • Epithelium is usually endometrioid but also ciliated, mucinous and even squamous
  • Stroma has polypoid or leaf-like projections into glandular lumina, resembling phyllodes tumor of breast
  • Stromal elements have mild or occasionally moderate atypia; resemble low grade endometrial stromal sarcoma but less bizarre and less undifferentiated
  • 33% have sarcomatous overgrowth
  • 25% - 47% are myoinvasive
  • 20% have multinucleated giant cells and heterologous elements (skeletal muscle)
  • May also have extensive stromal fibrosis
  • Occasionally sex cord like elements (Am J Clin Pathol 1989;91:664)
  • Usually 1+ mitotic figure/10 HPF in stromal cells
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Weijie Li, MD:

Fig 1: 2×; Figs 2 & 3: 10×; Fig 4: 20×; Fig 5: 40×

Images hosted on other servers:

Dilated glands surrounded by cuff of stomal cells (fig 1F)

Cambium layer

Benign epithelial cells and
malignant stromal cells
with mitotic figures

Epithelial glands
show prolif-
eration, but no
obvious atypia

Cambium layer with marked atypia

Malignant stromal cells

Cytology images

Images hosted on other servers:

Denuded malignant cells with variable sizes

Dense clusters of polymorphic tumor cells

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

Partly denuded tumor cells with fragile cytoplasm

Tumor cells have variable sizes

Positive stains
Mesenchymal component, in areas without sarcomatous overgrowth:
Electron microscopy description
  • Features of proliferative endometrium; stroma resembles endometrial stromal sarcoma or mixed müllerian tumor (Am J Clin Pathol 1979;71:112)
Differential diagnosis
  • Adenofibroma: may be extremely difficult to distinguish on a curettage specimen; no hypercellular stroma, no cambium layer, low mitotic index (< 2/10 HPF) and at most mild stromal nuclear atypia
  • Adenomyomatous polyp: attenuated surface endometrium on 3 sides; cystic change; large, thick walled blood vessels, no stromal hypercellularity, no cuffing and no atypia
  • Carcinosarcoma: malignant epithelial (at least focally) and sarcomatous elements
  • Embryonal rhabdomyosarcoma (children): evidence of skeletal muscle differentiation (histology, immunohistochemistry or EM)
  • Endometrial stromal sarcoma: often intravascular growth, tongue-like infiltration and arborizing vessels; may have glands, but they are smaller and not dilated; no periglandular stromal condensation, no intraluminal polypoid protrusions
  • Endometriosis, polypoid: resembles adenosarcoma particularly when occurring in cervix or peritoneum