Prostate gland & seminal vesicles
Phyllodes variant of STUMP

Editorial Board Member: Debra L. Zynger, M.D.
Kenneth A. Iczkowski, M.D.

Topic Completed: 1 October 2017

Minor changes: 8 September 2020

Copyright: 2003-2021,, Inc.

PubMed Search: prostatic phyllodes

Kenneth A. Iczkowski, M.D.
Page views in 2020: 526
Page views in 2021 to date: 26
Cite this page: Iczkowski KA. Phyllodes variant of STUMP. website. Accessed January 17th, 2021.
Definition / general
  • Variant or subtype of stromal tumor of uncertain malignant potential (STUMP)
  • < 100 reported cases
  • Tumor with cellular or sarcomatoid stroma and hyperplastic glands
  • Resembles breast tumor
  • Usually recurs after transurethral prostatic resection
Essential features
  • Age range 25 to 86 years (mean 55)
Clinical features
  • Urinary obstructive symptoms and hematuria
  • Recurrence seen in 7 of 14 low grade tumors (50%) (J Urol 2004;172:894)
    • Metastases to abdominal wall in one patient 11 years after initial diagnosis, following 3 recurrences
    • 22 year old man had lung metastasis
Prognostic factors
  • Histological grading is predictive of short term outcome based on the combination of stromal cellularity, cytological atypia, number of mitotic figures (> 5 mitotic figures / 10 HPF) and the stroma to epithelium ratio (J Urol 2004;172:894)
Case reports
  • Usually radical prostatectomy alone
  • One patient had a temporary response to radiotherapy and chemotherapy before death (Can Urol Assoc J 2014;8:E263)
  • Inoperable case managed by palliative treatment using luteinizing hormone releasing hormone analogue (BMJ Case Rep 2010 Dec 1;2010)
Gross description
  • Multiple cystic and solid areas
Microscopic (histologic) images

Contributed by Kenneth A. Iczkowski, M.D.

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Images hosted on other servers:

Pseudopapillary structures with cleft-like spaces

Phyllodes tumor

Laser microdissection

Positive stains
Molecular / cytogenetics description
Differential diagnosis
Board review style question #1
Phyllodes variant of STUMP:

  1. Has a stromal component that is positive for broad spectrum keratin
  2. Has grossly solid growth pattern
  3. If low grade, will rarely recur
  4. Is clinically malignant and metastasizes in most cases
  5. May present with markedly elevated PSA
Board review style answer #1
E. May present with markedly elevated PSA

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