Spermatocytic tumour

Spermatocytic tumour
Diagnosis in short
Spermatocytic tumour
Synonyms	spermatocytic seminoma (old term)
LM	three cell populations: (1) small cells (6-8 µm) - with a large NC ratio, (2) medium cells (15-18 µm) with prominent nucleoli and spireme chromatin, (3) Large cells (50-100 µm) with spireme chromatin; mucoid lakes, intratubular spread
LM DDx	DLBCL, seminoma
IHC	SALL4 +ve, OCT3/4 -ve, CD117 +ve/-ve
Site	testis
Signs	mass lesion
Prevalence	rare
Prognosis	benign, good
Clin. DDx	other germ cell tumours, lymphoma
Treatment	excision to exclude malignancy

Spermatocytic tumour is a rare benign testicular tumour.

It was previously known as spermatocytic seminoma. It should not be confused with seminoma which is an unrelated tumour.

General

• Rare tumour.
• Only one case of metastases in 200 cases.
• Orchiectomy is curative.
• Not reported/found in females.
• Typically older - mean age 50s.

Epidemiology

• Does not arise from germ cell neoplasia in situ (previously known as intratubular germ cell neoplasia) - not considered a subtype of seminoma.

Microscopic

Features:

• Population of three cells.
  1. Small cells (6-8 µm) - with a large NC ratio.
     • Look like secondary spermatocytes.
     • May be confused with (mature) lymphocytes.
  2. Medium cells (15-18 µm) with prominent nucleoli.
     • Filamentous chromatin (AKA spireme chromatin).
  3. Large cells (50-100 µm).
     • Filamentous chromatin.
• Mucoid lakes.
• Intratubular spread.

Notes:

• Spireme = the tangle of filaments in prophase portion of mitosis.
• May have eosinophilic cytoplasm (dependent on lab).
  • Usually larger than Leydig cell tumour.

DDx:

• DLBCL.
• Seminoma.

Images

• 

  Spermatocytic tumour - high mag. (WC)

• 

  Spermatocytic tumour - intermed. mag. (WC)

• 

  Spermatocytic tumour - high mag. (WC)

IHC

Features:

• PLAP -ve (0 positive/17).
• CD117 -ve (7 positive/17).
• CAM5.2 -ve (1 positive/17).

Others:

• SALL4 +ve.
• OCT3/4 -ve.
• AFP -ve.
• CD30 -ve.
• Beta-hCG -ve.

Sign out

Left Testis, Radical Orchiectomy:
	- Spermatocytic tumour, see comment.
	- NEGATIVE for germ cell neoplasia in situ.
	- Background testis with spermatogenesis and atrophy.

Comment:
Spermatocytic tumours are rare. They are not associated with germ cell neoplasia in situ (GCNIS) and typically not seen together with other germ cell types.  

The tumour stains as follows:
POSITIVE: CD117 (moderate, patchy), SALL4 (moderate, diffuse), BCL2 (scattered cells, moderate membranous).
NEGATIVE: AE1/AE3, AFP, CD31, CD34, calretinin, hCG, CD3, CD10, CD20, CD30, CD45, GATA3, PLAP, PSA, OCT3/4, CAM5.2, D2-40.

This tumour (spermatoctyic tumour) was previously known as "spermatocytic seminoma".  The term "spermatocytic seminoma" is no longer recommended by the World Health Organization, presumably as the name may: (1) create confusion with "seminoma" and (2) falsely raise the possibility of a mixed tumour (that develops in the context of GCNIS).

Micro

This tumour has three cell types with spireme chromatin in the larger and intermediate cell type. Infiltrating lymphocytes are absent.

The background testis has some spermatogenesis and atrophic change. Germ cell neoplasia in situ (GCNIS) is ABSENT. The seminiferous tubules adjacent to the tumour, where visualized, are atrophic.

See also

• Testis.
• Genitourinary pathology.