Benign tumors
Pseudosarcomatous fibroepithelial stromal polyps

Author: Nat Pernick, M.D. (see Authors page)

Revised: 3 November 2015, last major update March 2003

Copyright: (c) 2003-2015,, Inc.

PubMed Search: Pseudosarcomatous fibroepithelial stromal polyp
Definition / General
  • Resemble fibroepithelial stromal polyps of vagina, vulva and cervix, but with bizarre morphology, frequent mitoses (>10/10 HPF), atypical mitotic figures or hypercellularity
  • Median age 32 years, range 16-75 years
  • Often in pregnant patients
  • May recur locally; no metastases
  • Positive margin status, which is common, apparently not associated with recurrence
Gross Description
  • Often multiple lesions, particularly in pregnant women
Positive Stains
  • Desmin
Differential Diagnosis
  • Aggressive angiomyxoma: deep, prominent vascular pattern cuffed by myoid bundles
  • Angiomyofibroblastoma: well-circumscribed subserosal nodule, no atypia, stromal cells cluster around vessels, which usually have delicate walls
  • Botryoid embryonal rhabdomyosarcoma: early childhood, submucosal hypercellular zone/cambium layer, rhabdomyoblasts, myoglobin+, myogenin+
  • Cellular angiofibroma: well circumscribed, less polypoid, diffusely vascular with hyalinized walls, no atypical stromal cells, desmin-
  • Leiomyosarcoma: clear boundary of tumor cells with epithelium, smooth muscle differentiation
  • Low grade endometrial stromal sarcoma: vessels resemble spiral arterioles, no central vascular core, thick bands of collagen in starburst pattern, dot like staining of desmin or keratin
  • MPNST: perivascular accentuation, 50% are S100+
  • DFSP: CD34+, desmin-, storiform throughout
Additional References