Testis & epididymis
Germ cell tumors
Spermatocytic tumor

Topic Completed: 1 September 2012

Minor changes: 10 September 2020

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PubMed Search: Testis [title] spermatocytic tumor

Rafael Jimenez, M.D.
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Cite this page: Jimenez R. Spermatocytic tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisspermseminoma.html. Accessed January 17th, 2021.
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)
  • 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
  • Unlike classic seminoma, does not arise from intratubular germ cell neoplasia - may derive from differentiated spermatogonia
Clinical features
Prognostic factors
Case reports
  • Orchiectomy
Gross description
  • Pale gray, mucoid, edematous
  • Soft, friable cut surface
  • Mean 7 cm
  • 10% bilateral
Gross images

AFIP images

Mucoid tumor

Images hosted on other servers:

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

Case #448

Low power

High power

Various images



AFIP images

Diffuse growth pattern

Focal pseudoglandular pattern

Cystic pattern

cell population

Pattern of small
nests, trabeculae,
clusters and single cells

Filamentous chromatin

Normal spermatogenesis

Unusual features:


Tumor nests and cords mixed with lymphocytes

reaction and
lymphoid infiltrate

Intratubular component

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)
Positive stains
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

AFIP images

Intercellular bridge

Nest of spermatocytic seminoma

Molecular / cytogenetics description
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
Board review style answer #1
D. Sarcomatous change
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