Testis and epididymis
Germ cell tumors
Embryonal carcinoma

Author: Andres Matoso, M.D.

Revised: 17 January 2018, last major update January 2018

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Embryonal carcinoma [title] testis

Cite this page: Matoso, A. Embryonal carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/testisembryonal.html. Accessed February 25th, 2018.
Definition / general
  • Malignant germ cell tumor composed of primitive epithelial tumor cells recapitulating early stages of embryonic development
Essential features
  • Age at presentation: 30's
  • Pure in 2% of the cases; most commonly part of mixed germ cell tumor
  • More than 60% have metastases at presentation
  • Multiple morphologic patterns
Epidemiology
  • Peak age is 30 years, 10 years younger than seminoma
  • Rare in prepubertal children
  • Common as a component of mixed germ cell tumors (GCT) (40% of all mixed GCTs)
  • Rare in pure form, 2% of all GCTs
Sites
  • Testis
  • Retroperitoneum
Pathophysiology
  • Unknown
Etiology
  • Unknown
Clinical features
  • Painless swelling of the testis
  • Occasionally testicular pain
  • Gynecomastia
  • Symptoms related to metastasis
Diagnosis
  • Ultrasound of testis
Laboratory
  • Elevated LDH
Prognostic factors
  • Metastases are common at presentation (60%)
  • 95% cure rate after multimodal therapy including radical orchiectomy, retroperitoneal lymphadenectomy and chemotherapy
Case reports
Treatment
  • Radical orchiectomy in all patients
  • Retroperitoneal lymphadenectomy (optional)
  • Multidrug chemotherapy (cisplatin, bleomycin, etoposide, gemcitabine, vinblastine or ifosfamide)
Gross description
  • Soft, tan white, poorly circumscribed, with hemorrhage and necrosis
Gross images

Images hosted on other servers:

Pure embryonal carcinoma

Gray white mottled appearance

Embryonal carcinoma and teratoma

Microscopic (histologic) description
  • Solid, pseudoglandular, alveolar, tubular or papillary patterns
  • Primitive epithelial type cells with minimal features of differentiation
  • High grade features of large, epithelioid, anaplastic cells with prominent nucleoli, indistinct cell borders with nuclear overlapping, pleomorphism, frequent mitoses
  • Giant cells with granular, pink, amphophilic cytoplasm
  • Often mixed with other nonseminomatous germ cell tumors
  • No distinct fibrous septa
  • Intratubular embryonal carcinoma often present adjacent to invasive lesion, often with calcifications
  • Stromal component suggests presence of teratoma
  • Vascular invasion may be artifactual (loosely cohesive cells that don't conform to shape of vessel); true vascular invasion (groups of cells that conform to shape of vessel or are adherent by thrombus) is a poor prognostic factor and should be reported
Microscopic (histologic) images

Images hosted on PathOut server:

Images contributed by Andres Matoso, M.D.

Scant cytoplasm and numerous mitoses



Images hosted on other servers:

Sheets of blue cells

Primitive, anaplastic cells

Coagulative necrosis

Papillary pattern

Abundant cytoplasm

Syncytiotrophoblast


Solid sheets of anaplastic cells

Immature stroma

Intratubular

Intratubular CD30+

CD30+

Positive stains
  • CD30: highly sensitive and specific marker for embryonal carcinoma
  • Oct3 / 4: distinct nuclear staining but also positive in seminoma and intratubular germ cell neoplasia
  • SALL4
  • PLAP: usually patchy and weaker than in seminoma
  • Various cytokeratins
  • Focally positive for AFP in scattered tumor cells
Negative stains
Molecular / cytogenetics description
  • Isochrome 12p
  • More copy numbers associated with worse prognosis
Differential diagnosis
Board review question #1
Which of the following immunohistochemistry markers is positive in embryonal carcinoma and not in seminoma?

  1. CD30
  2. CD117
  3. OCT4
  4. SALL4

Board review answer #1
A. CD30
Board review question #2
Which of the following is a characteristic feature of embryonal carcinoma?

  1. Average age at presentation is 50 years
  2. Frequent in prepubertal children
  3. Metastases are frequent at presentation
  4. Most commonly presents in a pure form
Board review answer #2
C. Metastases are frequent at presentation
Board review question #3
Which one of the following therapies is used to treat embryonal carcinoma?

  1. Active surveillance
  2. Hormonal castration
  3. Partial orchiectomy
  4. Radical orchiectomy
Board review answer #3
D. Radical orchiectomy