Teratoma with somatic type malignancy

Testis and epididymis
Germ cell tumors
Teratoma with somatic type malignancy

Authors: Christopher Dall, M.D., Debra Zynger, M.D.

Topic Completed: 1 February 2018

Revised: 14 December 2019

Copyright: 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Teratoma with somatic type malignancy

Related topics: Angiosarcoma, Chondrosarcoma, Osteosarcoma, PNET

Page views in 2019: 2,696

Page views in 2020 to date: 337

Table of Contents

Cite this page: Dall C, Zynger D. Teratoma with somatic type malignancy. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisteratocarcinoma.html. Accessed February 20th, 2020.

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

Commonly metastatic at diagnosis (Eur J Radiol 2009;69:230)
Rhabdomyosarcoma most prevalent somatic type malignancy (J Urol 2016;196:95)
Must be distinguished from sarcomatoid yolk sac tumors which represent up to 60% of post chemotherapy sarcomatous tumors (Am J Surg Pathol 2015;39:251)

Terminology

Previously termed teratoma with malignant transformation and teratoma with somatic malignancy

Epidemiology

3 - 6% of testicular germ cell tumors with teratomatous components (Cancer 1985;56:860, Cancer 1984;54:1824, J Urol 1994;152:1144)
Median age of diagnosis in late 20s, similar to teratoma (Cancer 1985;56:860, Cancer 1984;54:1824)

Sites

90% with gonadal primary but primary tumor may be found in the mediastinum or retroperitoneum (J Urol 2016;196:95)

Pathophysiology

Two proposed origins of somatic malignancy (Eur Urol 2007;51:1306):
- Mature teratoma
- Embryonal carcinoma
Somatic malignancies generally have same genetic aberrancies as germ cell tumor (Am J Surg Pathol 2012;36:1849)
- Isochromosome 12p seen in many cases (J Urol 1998;159:133)

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

Diagnosis

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:

Ossified left retroperitoneal
mass in osteosarcoma type
malignant transformation

Adenocarcinoma type
malignant transformation
with ascites and
peritoneal thickening

Prognostic factors

Poorer prognoses compared with those without malignant transformation due to higher likelihood of metastatic disease at presentation (J Urol 1998;159:859, J Urol 2016;196:95, Am J Surg Pathol 2007;31:1356)
Traditional International Germ Cell Cancer Collaborative Group (IGCCCG) prognostic factors may be less significant (J Urol 2014;192:1403)
Disease confined to the primary site generally has favorable prognosis
Sarcomatous components portend a worse prognosis (Am J Surg Pathol 2007;31:1356)

Case reports

28 year old man with late recurrence of teratoma with 2 somatic type malignancies (Int J Dev Biol 2013;57:153)
35 year old man with intracranial somatic malignancy (Rom J Morphol Embryol 2016;57:1389)

Treatment

Surgical resection mainstay of treatment
Chemotherapy based on histologic subtype of malignant transformation (J Clin Oncol 2003;21:4285)
Less responsive to cisplatin based therapy (J Urol 2014;192:1403)
Radical surgery often utilized for advanced disease (J Urol 1998;159:133)

Gross images

Image contributed by Christopher Dall, B.S. and Debra L. Zynger, M.D.

Retroperitoneal metastasis with sarcoma NOS

Microscopic (histologic) description

Atypical mesenchymal or epithelial cells occupying ≥ 1 low power field (4x objective, 5 mm in diameter) (IARC: WHO Classification of Tumours of the Urinary System and Male Genital Organs, 4th Edition, 2016)
- May have infiltrative or expansive histology
Somatic type malignancies differ in prevalence (IARC: WHO Classification of Tumours of the Urinary System and Male Genital Organs, 4th Edition, 2016, J Urol 1998;159:859)
- Sarcoma most common (63%) with rhabdomyosarcoma (35%) and sarcoma, not otherwise specified (24%), comprising the majority of cases
- Adenocarcinoma makes up an additional 22% of cases
- Primitive neuroectodermal tumor and squamous cell carcinomas next most frequent

Microscopic (histologic) images

Images hosted on PathOut servers:

Images contributed by Christopher Dall, B.S. and Debra L. Zynger, M.D.

Rhabdomyosarcoma in metastatic testicular germ cell tumor

Chondrosarcoma in metastatic testicular germ cell tumor

Primative neuroectodermal tumor within testis

Positive stains

Desmin, myogenin, vimentin depending on type of sarcoma
Cytokeratin, epithelial membrane antigen if carcinoma (Virchows Arch 2012;461:27)

Negative stains

PLAP, alpha-fetoprotein (AFP), hCG, OCT4 (Virchows Arch 2012;461:27)

Differential diagnosis

Choriocarcinoma: cytotrophoblasts mimic squamous cell carcinoma but express β-hCG
Metastasis of non germ cell tumor: primary sarcoma or carcinoma
Teratoma without somatic type malignancy: malignant appearing somatic cells do not occupy ≥ 1 low power field at 4x magnification
Yolk sac tumor (glandular or sarcomatoid): positive for GPC3, keratin and AFP (Am J Surg Pathol 2014;38:1396, Am J Surg Pathol 2015;39:251)

Board review style question #1

Adenocarcinoma
Primitive neuroectodermal tumor
Rhabdomyosarcoma
Sarcoma, not otherwise specified
Squamous cell carcinoma

Board review answer #1

C. Rhabdomyosarcoma

Board review style question #2

Isochromosome 12p
MYC amplification
TERT promoter mutation
Upregulation of ERG

Board review answer #2

A. Isochromosome 12p