Testis & epididymis
Sex cord-stromal tumors
Mixed-other
Author: Swapnil U. Rane, M.D.
Topic Completed: 1 August 2013
Minor changes: 10 September 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Mixed germ cell sex cord stromal tumors testis
Related topics: Mixed germ cell - sex cord stromal tumors: gonadoblastoma
Table of Contents
Definition / general | Terminology | Epidemiology | Clinical features | Case reports | Treatment | Gross description | Microscopic (histologic) description | Positive stains | Negative stains | Molecular / cytogenetics description | Comparison of tumors with and without gonadoblastoma | Differential diagnosisCite this page: Rane S. Mixed-other. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testismixedother.html. Accessed January 17th, 2021.
Definition / general
- Gonadal neoplasm composed of germ cells associated with sex cord stromal tumor without any evidence of gonadoblastoma
- Most cases have been described in ovaries, only a few cases reported in testis
Terminology
- Also called pflügeroma (Bull Soc Anat Paris 1912;14:403), epitheliomas pflügeriens (Mason P (1923) In: diagnostics de Laboratoire. Maloine Editions, Paris, pp 477), tumor of gonadal analage with female differentiation (Arch Anat Cytol Pathol 1990;38:11)
Epidemiology
- Rare; occur in gonads of phenotypically and genetically normal subjects
- Usually ages 30 - 69 years in normally descended testis
Clinical features
- Presents as asymptomatic, gradually enlarging scrotal mass, often over many years
- Normal serum AFP, CEA, β-hCG
- Benign behavior with no metastases reported in testicular or ovarian tumors
Case reports
- Adult man (Am J Clin Pathol 1981;75:565)
- Incidental finding (J Urol 1995;154:1479)
Treatment
- Radical orchidectomy; nodal dissection probably not indicated unless clinical involvement
Gross description
- Well circumscribed, white, soft, with compressed normal testicular parenchyma at periphery
- Variable cystic change (Virchows Arch 2006;448:612)
- No involvement of testicular adnexa or tunica albuginea
Microscopic (histologic) description
- Germ cells arranged in groups or as solitary units within background of dense, diffuse proliferation of spindle shaped sex cord stromal cells
- Germ cell groups are not uniformly scattered; microscopic foci can show predominance of either cell type
- Germ cells:
- Variable size but abundant clear cytoplasm, variably blastic nucleus with fine chromatin, 1+ inconspicuous nucleoli
- Variable grade; may have targetoid appearance if small nuclei and abundant cytoplasm
- Unlike ovarian counterpart, squaring off of nuclei is typically absent
- Sex cord stromal elements:
- Spindle cells with nuclei showing longitudinal clefts and inconspicuous nucleoli
- Can show palisading
- Tumor cells may be intermixed with dense collagen
- Cells may be arranged around collagen forming Call-Exner-like bodies
- No concentric calcifications, Leydig cells, lutein cells
Positive stains
Molecular / cytogenetics description
- Ovarian tumors have c-kit mutations (seen in seminomas) and excess genetic material on #12p (seen in all germ cell tumors) but no genetic aberrations identified in testicular tumors (Virchows Arch 2006;448:612)
Comparison of tumors with and without gonadoblastoma
- MSGCT - gonadoblastoma:
- Associated with disorders of sexual development (gonadal dysgenesis [pure or mixed], altered karyotype, pseudohermaphrodites with streak gonads)
- Leydig-like cells and lutein cells
- Virilization
- Proliferative activity only in germ cells
- MGSCT - not gonadoblastoma:
- Genetically and phenotypically normal individuals
- No Leydig-like cells and lutein cells
- No endocrine effects usually; if present, usually feminization
- Proliferative activity in sex cord stromal and germ cell components
Differential diagnosis
- Pure Sertoli - Leydig cell tumors: lack sex cord stromal elements
- Sex cord stromal tumors with entrapped germ cells:
- Entrapped germ cells predominantly in clusters at edge of tumor, unlike germ cells in MGSCT which are almost always surrounded by sex cord stromal cells
- Entrapped germ cells appear benign and do not show anaplasia or abnormal mitoses (Am J Surg Pathol 2000;24:535)
