Fallopian tubes
Adenomatoid tumor

Author: Nicole Riddle, M.D. (see Authors page)
Editor: Jamie Shutter, M.D.

Revised: 11 August 2017, last major update September 2013

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

PubMed Search: Adenomatoid tumor fallopian tubes

Cite this page: Adenomatoid tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/fallopiantubesadenomatoid.html. Accessed November 18th, 2018.
Definition / general
  • Most common benign fallopian tube tumor, usually asymptomatic
  • Also called benign mesothelioma
  • Often occurs in middle aged or older females
  • May be due to invaginations of visceral mesothelium
  • Uterus, ovary, para-ovarian
  • Similar behavior as tumor in paratesticular region
Gross description
  • Usually incidental, unilateral, microscopic finding within myosalpinx (muscle layer)
  • May be circumscribed, gray white yellow, firm nodule up to 3 cm
Gross images

Images hosted on PathOut server:

Well circumscribed mass

Microscopic (histologic) description
  • Usually tubular spaces of varying size composed of flattened cells resembling endothelium
  • Rarely large cells with eosinophilic cytoplasm
  • Often with smooth muscle hyperplasia, lymphocytic follicles
  • May have cytoplasmic vacuoles, infiltrative-like borders, clusters or small cords of cells
  • Rare mitotic figures, minimal atypia
  • May resemble vacuoles, fat cells, vessels, artifact
Microscopic (histologic) images

Images hosted on PathOut server:

Tubal wall expanded

Slit-like, gland-like structures

Cysts are conspicuous

Vacuoles and gland-like spaces

Abundant eosinophilic cytoplasm with few vacuoles

Vacuoles and
spaces separated
by scanty stroma

Images hosted on other servers:

Tubule-like spaces lined by flattened cells

Numerous tubular
vascular spaces

Flattened lining

Negative stains
Differential diagnosis
  • Adenomyoma: more prominent smooth muscle
  • Invasive / metastatic well differentiated carcinoma: not circumscribed, more atypia and mitotic activity, different immunohistochemical profile
  • Lymphangioma: cells very flattened, calretinin-