Testis and epididymis
Germ cell tumors
Spermatocytic tumor

Author: Rafael Jimenez, M.D. (see Authors page)

Revised: 21 July 2017, last major update September 2012

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Testis [title] spermatocytic tumor

Cite this page: Spermatocytic tumor. PathologyOutlines.com website. http://pathologyoutlines.com/topic/testisspermseminoma.html. Accessed December 14th, 2017.
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
Prognostic factors
Case reports
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

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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



Images hosted on other servers:

Various images

Numerous apoptotic cells

No lymphocytes or granulomas

Edema fluid filled spaces



Unusual features:

Rhabdomyosarcomatous component is desmin+

Sarcomatous component

MAGE-A4+ (also present in spermatogonia)

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
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
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+