Testis & paratestis
Mesothelial tumors
Well differentiated papillary mesothelial tumor
Author: Jennifer Gordetsky, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 1 November 2013
Last staff update: 20 October 2022
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Well differentiated papillary mesothelial tumor
Related topics: Malignant mesothelioma
Table of Contents
Definition / general | Epidemiology | Sites | Clinical features | Diagnosis | Case reports | Radiology images | Treatment | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Electron microscopy description | Differential diagnosis | Additional referencesCite this page: Gordetsky J. Well differentiated papillary mesothelial tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testismesothelioma.html. Accessed June 2nd, 2023.
Definition / general
- Histologic variant of mesothelioma composed entirely of bland papillary structures and tubules with no identifiable invasion
Epidemiology
- Usually occurs in the peritoneum of young women
- Few cases reported in the tunica vaginalis of the testis
- Ages ranging from 18 to 69
Sites
- Peritoneum and tunica vaginalis
Clinical features
- Scrotal / peritesticular mass, associated with hydrocele
Diagnosis
- Mesothelial origin can be confirmed by immunohistochemical stains
Case reports
- 18 year old man with hydrocele (J Clin Pathol 1992;45:1029)
- 35 year old man with bilateral hydroceles (Urol Oncol 2006;24:36)
- 48 year old man without asbestos exposure (Korean J Pathol 2014;48:225)
Radiology images
Images hosted on other servers:
Scrotal ultrasound
Treatment
- Complete excision
Microscopic (histologic) images
Images hosted on other servers:
Typical tubulopapillary pattern
Psammoma body in papillary area
Bland papillary structures
Cytology description
- Moderately cellular, uniform epithelioid cells arranged in papillary groups with fibrovascular cores
- Cells have moderate cytoplasm, uniform round nuclei, distinct nucleoli
- Minimal atypia
- Few lymphocytes scattered in the background
- No mitoses
Electron microscopy description
- Tumor cells are round to polygonal in shape with numerous short and long slender microvilli on the free surfaces
- Cytoplasmic organelles include moderate amounts of mitochondria, moderate amounts of rough endoplasmic reticulum, free ribosomes and microfilaments
- Centrally located oval nuclei, euchromatin and prominent nucleoli
- Well developed desmosomes (Pathol Res Pract 2010;206:105)
Differential diagnosis
Additional references
