Testis & epididymis
Germ cell tumors
Spermatocytic tumor
Author: Rafael Jimenez, M.D.
Topic Completed: 1 September 2012
Minor changes: 28 March 2019
Copyright: 2002-2018 PathologyOutlines.com, Inc.
PubMed Search: Testis [title] spermatocytic tumor
Table of Contents
Definition / general | Epidemiology | Etiology | Clinical features | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Negative stains | Electron microscopy description | Electron microscopy images | Molecular / cytogenetics description | Differential diagnosis | Board review style question #1 | Board review answer #1Cite this page: Jimenez R. Spermatocytic tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisspermseminoma.html. Accessed August 13th, 2020.
Definition / general
- Germ cell tumor not related to classic seminoma; does not arise from intratubular germ cell neoplasia
- Contains 3 cell types, varying from lymphocyte size to multinucleated giant cells but mostly composed of intermediate sized cells (Arch Pathol Lab Med 2009;133:1985)
Epidemiology
- Rare; 1 - 4% of all seminomas (J Urol 2007;178:125)
- Mean age 55 years but also occurs in younger patients (Eur Urol 2004;45:495)
- Note: the most common testicular tumor in men age 60+ years is diffuse large B cell lymphoma
Etiology
- Unlike classic seminoma, does not arise from intratubular germ cell neoplasia - may derive from differentiated spermatogonia
Clinical features
- Only occurs in descended testes (not extragonadal or in female gonad)
- Benign (rare documented cases with metastases) but 6% are associated with a sarcomatous component, distant metastases and poor prognosis (Am J Clin Pathol 1990;94:89, Am J Surg Pathol 1988;12:75)
Prognostic factors
- Sarcomatous component is poor prognostic factor (Am J Surg Pathol 1988;12:75)
Case reports
- 49 year old man with a testicular mass (Case of the Week #448)
- 55 year old man with tumor that underwent rhabdomyosarcomatous transformation (J Cancer Res Ther 2009;5:213)
Treatment
- Orchiectomy
Gross description
- Pale gray, mucoid, edematous
- Soft, friable cut surface
- Mean 7 cm
- 10% bilateral
Gross images
Images hosted on PathOut server:
Mucoid tumor
Images hosted on other servers:
Nodular gray white tumor
Cystic and mucoid tumor
Microscopic (histologic) description
- Nodules of cells with edema filled spaces causing pseudoalveolar appearance
Three types of cells:
- Small cells (6 - 8 microns) with narrow rim of eosinophilic cytoplasm resembling lymphocytes
- Medium cells (15 - 18 microns) with round nuclei, filamentous chromatin and eosinophilic cytoplasm (resemble spermatocytes but diploid)
- Giant cells (50 - 100 microns) with one or more nuclei
- Increased number of apoptotic cells (Mod Pathol 2007;20:1036)
- May have numerous mitoses
- Usually no stroma, no lymphocytes, no glycogen, no granulomas
- Usually not associated with intratubular germ cell neoplasia or other types of germ cell neoplasia
- 6% of cases are associated with a sarcomatous component, which is usually intermingled with the spermatocytic seminoma cells
- The sarcomatous component is usually undifferentiated or shows muscle differentiation
- Anaplastic variant: focal areas of predominantly medium cells containing prominent nucleoli; no clinical evidence of aggressive behavior (Hum Pathol 1996;27:650)
Microscopic (histologic) images
Images hosted on PathOut server, contributed by Dr. Debra Zynger, COW #448:
Low power
High power
OCT34
CD45
Other images hosted on PathOut server:
Diffuse growth pattern
Large nodules have focal pseudoglandular pattern
Edema has caused a cystic pattern
Polymorphic population of mainly
small cells with dark nuclei,
intermediate cells with pale nuclei and
occasional multinucleated giant cells
Extensive intercellular
edema causes a pattern
of small nests, trabeculae,
clusters and single cells
Intratubular growth:
note the filamentous
("spireme") chromatin in
some of the larger cells
Intratubular growth:
one tubule shows
normal spermatogenesis
Unusual features:
Rhabdomyo-sarcomatous component is desmin+
Tumor nests and cords mixed with lymphocytes
Prominent
granulomatous
reaction and
lymphoid infiltrate
Intratubular component
surrounded by sarcomatous
growth with features of
embryonal rhabdomyosarcoma
Cytology description
- Clean background; three populations of cells (small, medium and large), with a preponderance of medium sized cells showing visible nucleoli; low mitotic rate; no lymphocytes (Diagn Cytopathol 1999;20:233)
Cytology images
Images hosted on other servers:
Numerous small lymphocyte-like cells, intermediate cells with filamentous chromatin and rare giant cells
Positive stains
- CAM5.2 (40%)
Negative stains
Electron microscopy description
- Cytoplasmic bridges between tumor cells resembles those between spermatocytes
- Thickening of plasma membrane, microtubules between cells
- Minimal or no glycogen
Electron microscopy images
Images hosted on PathOut server:
Intercellular bridge
joins two tumor
cells, as in normal
spermatocytes
A nest of spermatocytic seminoma is surrounded
by a well defined basement membrane; there are
numerous mitochondria, a Golgi apparatus and
round nuclei with dispersed chromatin
Molecular / cytogenetics description
- Gain of #9 (Cancer Res 2006;66:290)
Differential diagnosis
- Classic seminoma: fibrous stroma with prominent lymphocytes, often granulomatous reaction, seminoma cells have squared off nuclei; also intratubular germ cell neoplasia; lacks 3 cell types; PLAP+, PAS+ (glycogen), OCT3 / 4+
- Embryonal carcinoma: has markedly atypical cells, intratubular germ cell neoplasia; lacks 3 distinct cell types, AE1 - AE3+, OCT3 / 4+, CD30+
Board review style question #1
In a spermatocytic tumor, which of the following histologic finding incurs a worse prognosis
A. Anaplastic change
B. Anaplastic change and sarcomatous change
C. Germ cell neoplasia in situ
D. Sarcomatous change
A. Anaplastic change
B. Anaplastic change and sarcomatous change
C. Germ cell neoplasia in situ
D. Sarcomatous change
Board review answer #1
D. Sarcomatous change
