Mesenchymal / mixed epithelial & mesenchymal tumors

Atypical polypoid adenomyoma

Topic Completed: 1 May 2007

Minor changes: 16 November 2020

Copyright: 2007-2021, PathologyOutlines.com, Inc.

PubMed Search: Atypical polypoid adenomyoma cervix

Branko Perunovic, D.M.
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Cite this page: Perunovic B. Atypical polypoid adenomyoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cervixapa.html. Accessed November 29th, 2021.
Definition / general
  • Also called atypical polypoid adenomyofibroma, APA
  • Tumor of endometrium, lower uterine segment and endocervix composed of atypical complex glands with squamous metaplasia mixed with myofibromatous stroma
  • Uncommon (< 150 cases reported), associated with Turner syndrome
  • Mean age 40 years, range 21 - 73 years
  • Symptoms of dysfunctional uterine bleeding
  • May persist or recur, but does not metastasize; may have increased risk for later carcinoma; may be contiguous with adenocarcinoma
  • Should be considered in differential diagnoses of atypical glandular cells
Case reports
  • Conservative polypectomy and curettage or simple hysterectomy in peri / postmenopausal women but with follow up
Gross description
  • Resembles endometrial polyp
  • Single, well - circumscribed, polypoid mass up to 2 cm
  • Usually confined to endometrium with pushing margin
  • Remaining endometrium is often unremarkable
Microscopic (histologic) description
  • Biphasic with hyperplastic and atypical endometrial glands (complex architecture, often severe cytologic atypia), separated by fascicles of bland smooth muscle and fibrous storm
  • Squamous metaplasia present (90%), often extensive or with central necrosis
  • Minimal mitotic activity (< 3 mitotic figures per 10 HPF)
  • No desmoplasia
  • Low malignant potential - with features resembling well differentiated adenocarcinoma
Microscopic (histologic) images

AFIP images
Cytology description
  • Tightly backed clusters of glandular cells and loose aggregates of bland smooth muscle cells in premenopausal patients (Diagn Cytopathol 2000;22:176)
Positive stains
Differential diagnosis
Additional references
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