Testis and epididymis
Germ cell tumors
Teratoma with somatic type malignancy

Author: Christopher Dall, B.S.
Editor: Debra L. Zynger, M.D.

Revised: 27 February 2018, last major update February 2018

PubMed Search: Teratoma with somatic type malignancy

Related topics: Angiosarcoma, Chondrosarcoma, Osteosarcoma, PNET
Cite this page: Dall, C. Teratoma with somatic type malignancy. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/testisteratocarcinoma.html. Accessed March 20th, 2018.
Definition / general
  • Testicular germ cell tumor with somatic malignancy arising from germ cell tumor progenitor cells that occupies ≥ 1 microscopic field using 4x objective
Essential features
  • Previously termed teratoma with malignant transformation and teratoma with somatic malignancy
  • 90% with gonadal primary but primary tumor may be found in the mediastinum or retroperitoneum (J Urol 2016;196:95)
Clinical features
  • Somatic malignancies more commonly found as relapse, rather than at initial diagnosis (J Urol 2014;192:1403)
  • Timing of relapse varies based on type of somatic malignancy (J Urol 2014;192:1403)
    • Carcinomas diagnosed later than sarcomas
  • Scarce data regarding differences in presentation of somatic type malignancy and germ cell tumors
  • Found as metastatic disease, within the testis or both (J Urol 1998;159:133)
  • Histologic features and immunohistochemistry determine somatic malignancy subtype
Radiology description
  • Imaging may suggest specific somatic malignancy in germ cell tumors (Eur J Radiol 2009;69:230)
    • Ossified lymph nodes and soft tissue reported in osteosarcoma
    • Peritoneal carcinoma seen in adenocarcinoma
    • Septal thickening and opacifications reported in a case of bronchoalveolar carcinoma
Radiology images

Images hosted on other servers:
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Ossified left retroperitoneal
mass in osteosarcoma type
malignant transformation
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Adenocarcinoma type
malignant transformation
with ascites and
peritoneal thickening
Prognostic factors
Case reports
Gross images

Image contributed by Christopher Dall, B.S. and Debra L. Zynger, M.D.
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Retroperitoneal metastasis with sarcoma NOS

Microscopic (histologic) description
Microscopic (histologic) images

Images hosted on PathOut servers:

Images contributed by Christopher Dall, B.S. and Debra L. Zynger, M.D.
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Rhabdomyosarcoma in metastatic testicular germ cell tumor

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Chondrosarcoma in metastatic testicular germ cell tumor

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Primative neuroectodermal tumor within testis

Positive stains
Differential diagnosis
Board review question #1
    Teratoma with somatic type malignancy most commonly contains what histologic type?

  1. Adenocarcinoma
  2. Primitive neuroectodermal tumor
  3. Rhabdomyosarcoma
  4. Sarcoma, not otherwise specified
  5. Squamous cell carcinoma
Board review answer #1
C. Rhabdomyosarcoma
Board review question #2
    Which genetic feature would be most commonly found in teratoma with somatic type malignancy?

  1. Isochromosome 12p
  2. MYC amplification
  3. TERT promoter mutation
  4. Upregulation of ERG
Board review answer #2
A. Isochromosome 12p