Prostate gland & seminal vesicles
Phyllodes variant of STUMP
Author: Kenneth A. Iczkowski, M.D.
Editorial Board Member: Debra L. Zynger, M.D.
Topic Completed: 1 October 2017
Minor changes: 8 September 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: prostatic phyllodes
Table of Contents
Definition / general | Essential features | Epidemiology | Sites | Clinical features | Laboratory | Prognostic factors | Case reports | Treatment | Gross description | Microscopic (histologic) images | Positive stains | Molecular / cytogenetics description | Differential diagnosis | Board review style question #1 | Board review style answer #1Cite this page: Iczkowski KA. Phyllodes variant of STUMP. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/prostatephyllodes.html. 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
- Can be clinically benign (Can Urol Assoc J 2014;8:E548) or malignant (Can Urol Assoc J 2014;8:E263)
- Of 23 cases in one study, most were low grade (14), followed by intermediate grade (7) and high grade (2) (J Urol 2004;172:894)
Epidemiology
- Age range 25 to 86 years (mean 55)
Sites
- Usually prostate but has been reported in seminal vesicle (J Int Med Res 2010;38:1861)
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
Laboratory
- PSA elevated to 20.65 ng/ml (Diagn Pathol 2015;10:69), 60.76 ng/ml (Pathol Int 2012;62:204), or 192.8 ng/ml (BMJ Case Rep 2010 Dec 1;2010)
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
- 47 year old man (Pathol Int 2012;62:204)
- 53 year old man with large benign tumor (Arch Pathol Lab Med 1992;116:195)
- 60 year old man (J Oncol 2009;2009:241270)
- 67 year old man with malignant tumor (Pathol Int 2002;52:777)
- Malignant tumor (Arch Pathol Lab Med 1992;116:296)
Treatment
- 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.
Low power
High power
Images hosted on other servers:
Pseudopapillary structures with cleft-like spaces
Phyllodes tumor
Laser microdissection
Positive stains
- Stromal cells: Strongly positive for vimentin and actin
- Luminal epithelial cells: positive for prostate specific antigen, prostatic acid phosphatase and broad spectrum keratin AE1 / AE3
- Basal cells: positive for high molecular weight keratin 34βE12
Molecular / cytogenetics description
- Losses of chromosomes 1p, 6, 10, 11, 13, 14, 15q11-q21, 19p13, 22q described (Mod Pathol 2013;26:1536)
Differential diagnosis
- Benign prostatic hyperplasia: nodules consisting of stroma only, stroma and glands or glands only, without cleft-like spaces, stromal atypia or pseudopapillary structures
- Prostatic stromal sarcoma: lacks a glandular component
- Sarcomatoid carcinoma: biphasic tumor in which stromal component is cytokeratin positive.
Board review style question #1
Phyllodes variant of STUMP:
- Has a stromal component that is positive for broad spectrum keratin
- Has grossly solid growth pattern
- If low grade, will rarely recur
- Is clinically malignant and metastasizes in most cases
- May present with markedly elevated PSA
Board review style answer #1
