Testis & epididymis
Germ cell tumors
PNET
Author: Turki Al-Hussain, M.D.
Topic Completed: 1 January 2013
Minor changes: 9 September 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: PNET testis
Table of Contents
Definition / general | Case reports | Gross description | Microscopic (histologic) description | Positive stains | Electron microscopy descriptionCite this page: Al-Hussain T. PNET. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testispnet.html. Accessed January 20th, 2021.
Definition / general
- Primitive NEuroectodermal Tumor / Ewing sarcoma
- Frequent "nongerm cell" tumor in patients with testicular germ cell tumors (Mod Pathol 2010;23:972)
- Composed entirely of immature neural tissue
- Considered a monodermal teratoma
- Often fatal if metastases present (extratesticular), longer survival if neuroblastoma-like metastases
- May arise in germ cell tumors and be testicular, extratesticular or both (Am J Surg Pathol 1997;21:896)
Case reports
- 30 year old man who died of testicular tumor with widespread metastases (Arch Pathol Lab Med 1983;107:643)
- 46 year old man (Hum Pathol 2009;40:893)
Gross description
- Grayish white, necrotic
Microscopic (histologic) description
- Small cells with minimal cytoplasm in sheets, tubules, rosettes, pseudorosettes, medullary tubules and focally forming glia; overt overgrowth over immature teratoma by these cells
Positive stains
- Synaptophysin, NSE, chromogranin, HBA-71, GFAP, CD99, FLI1
Electron microscopy description
- Neurosecretory granules
