Spermatocytic Seminoma

Steven S. Shen, MD, PhD

Mahul B. Amin, MD

Jae Y. Ro, MD, PhD

Key Facts

Terminology

Germ cell tumor composed of 3 cell types of variable sizes ranging from 6-100 µm

Clinical Issues

Extremely rare
Age range: 25-87 years

Macroscopic Features

Well-circumscribed, soft, friable, tan-gray mass with mucoid or gelatinous, bulging cut surface

Microscopic Pathology

Diffuse or solid sheet pattern with scant fibrous or edematous stroma is most common finding
Rare growth patterns include pseudoglandular, microcystic, trabeculae, nests, or single cells
Polymorphous cell population is hallmark of spermatocytic seminoma
Small lymphocyte-like cells: 6-8 µm; densely hyperchromatic nuclei and scant amount of eosinophilic to basophilic cytoplasm
Intermediate cells: 15-20 µm; most common cell type; round nuclei, finely granular chromatin, moderate amount of cytoplasm
Giant cells: 50-100 µm; least common cell type; distinctive filamentous or “spireme-type” chromatin

Ancillary Tests

Negative for most germ cell-associated markers (Oct3/4, Podoplanin(D2-40), PLAP, α-fetoprotein, glypican-3, HCG, and CD30[BerH2])

Low-power view of diffuse growth pattern of spermatocytic seminoma reveals no fibrovascular septae and no lymphocytic or granulomatous inflammation, typical features of classic seminoma.

This high-power photomicrograph shows the characteristic 3 cell types in SS: Small lymphocyte-like cells

with darkly stained nuclei, intermediate

and giant cells with “spireme-type” chromatin

TERMINOLOGY

Abbreviations

Spermatocytic seminoma (SS)

Definitions

Germ cell tumor recapitulating spermatogenic sequence composed of 3 cell types of variable sizes, ranging from 6-100 µm

ETIOLOGY/PATHOGENESIS

Cytogenetic Changes

Diploid or near hypodiploid, different from that of seminoma
Chromosomal numerical changes (most commonly gain of chromosome 9)

CLINICAL ISSUES

Epidemiology

Incidence
- Extremely rare; only 2 major series reported
- Bilaterality (up to 9%) is more common than in seminoma
- Occurs only in testis; no ovarian counterpart, no extragonadal primary tumors
- No race predilection as in other germ cell tumors
- Not associated with cryptorchidism
Age
- Range: 25-87 years (average: 53.6 years)
- Rare under 30 years

Presentation

Painless testicular swelling and mass
Serum tumor markers are not elevated

Treatment

Radical inguinal orchiectomy alone is curative
Postoperative prophylactic radiation or chemotherapy do not offer additional benefit and not routinely recommended

Prognosis

Excellent prognosis with rare malignant behavior (less than 1%)
Sarcomatoid transformation is rare, but when present is associated with distant metastasis and death

MACROSCOPIC FEATURES

General Features