Testis & epididymis
Germ cell tumors

Topic Completed: 1 July 2017

Minor changes: 10 September 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed Search: Testis [title] teratoma [title] "loattrfree full text"[sb]

Christopher Dall, M.D.
Debra Zynger, M.D.
Page views in 2019: 14,029
Page views in 2020 to date: 11,662
Cite this page: Dall C, Zynger D. Teratoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/testisteratoma.html. Accessed September 30th, 2020.
Definition / general
  • Tumor originating from germ cells with more than one embryonic germ layer
  • Postpubertal type associated with germ cell neoplasia in situ (GCNIS) and chromosome 12p amplification (Med Surg Urol 2014;3:1)
    • Thought to arise from GCNIS
  • Prepubertal is not associated with GCNIS or chromosome 12p amplification (Med Surg Urol 2014;3:1)
    • Prepubertal type significantly less likely to metastasize or recur
Clinical features
  • Ultrasound is used to evaluate a testicle mass
  • Avoid biopsies to prevent cancer seeding
  • Radical orchiectomy is initial procedure to diagnose a testicular mass in an adult
  • Increasing rate of antenatal diagnoses (J Pediatr Surg 2006;41:1513)
  • May use intraoperative frozen sections to guide therapy in pediatric populations
Radiology description
  • Ultrasound is used to help exclude benign pathology
  • Imaging may demonstrate calcifications or predominantly cystic lesions
  • Computed tomography of the chest and abdomen used for staging purposes
Radiology images

Images hosted on other servers:

Testicular teratoma diagnosed in utero

Demonstrating vascularity
of testicular teratoma
with calcifications

Prognostic factors
Case reports
  • Radical orchiectomy is first line therapy for testicular mass in an adult
  • Increasing rate of testis sparing surgery for prepubertal tumors (Rev Urol 2004;6:11)
  • Retroperitoneal lymph node dissection and platinum based chemotherapy are adjunctive therapies for testicular germ cell tumor
  • Treatment guidelines are based on postorchiectomy TNM stage (NCCN guidelines: Testicular Cancer)
  • Consider sperm preservation options
Gross description
  • Lobulated, with cysts of mucinous, gelatinous or serous material
Gross images

Contributed by Debra L. Zynger, M.D.

Teratoma (100%)

Mixed GCT

Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Debra L. Zynger, M.D.

Cartilage surrounded by mitotically active spindle cells

Gastrointestinal epithelium

Squamous epithelium

Cellular mesenchyme

Loose mesenchyme


Molecular / cytogenetics description
Sample pathology report
  • Right testicle, radical orchiectomy:
    • Mixed germ cell tumor, teratoma (55%), seminoma (20%), embryonal carcinoma (10%), yolk sac tumor (10%) and choriocarcinoma (5%) types (see synoptic report)
Differential diagnosis
Board review style question #1

A 27 year old man presents with a painless enlarging testicular mass. He undergoes appropriate workup and orchiectomy confirms diagnosis of a pure postpubertal teratoma. Which of the following is likely to be true?

  1. AFP is likely elevated
  2. Cytogenetic analysis will reveal chromosomal abnormalities
  3. Few mitotic figures will be identified microscopically
  4. Hair follicles are likely to be seen microscopically
  5. He has a poor prognosis
Board review answer #1
B. Cytogenetic analysis will reveal chromosomal abnormalities
Board review style question #2
A 37 year old woman gives birth to a male baby who is diagnosed with an undescended testicle. Further workup reveals a large intra abdominal mass, which is resected. Pathology is consistent with a pure teratoma. Which of the following is most likely present on microscopic examination?

  1. Adjacent areas of germ cell neoplasia in situ
  2. Areas with organoid morphology
  3. Many mitotic figures and cytologic atypia
  4. Sarcomatous elements
  5. Significant areas of testicular tubular atrophy
Board review answer #2
B. Areas with organoid morphology
Back to top
Image 01 Image 02