Testis & paratestis
Germ cell tumors
Teratoma with somatic type malignancy
Authors: Christopher Dall, M.D., Debra L. Zynger, M.D.
Last author update: 23 January 2022
Last staff update: 21 November 2022 (update in progress)
Copyright: 2002-2022, PathologyOutlines.com, Inc.
PubMed Search: Teratoma with somatic type malignancy
See Also: Teratoma
Table of Contents
Definition / general | Essential features | Terminology | Epidemiology | Sites | Pathophysiology | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosis | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Dall C, Zynger DL. Teratoma with somatic type malignancy. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisteratocarcinoma.html. Accessed December 10th, 2022.
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
Adenocarcinoma type
malignant transformation
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
Contributed by Christopher Dall, M.D. and Debra L. Zynger, M.D.
Retroperitoneal metastasis with sarcoma, NOS
Lung metastasis with rhabdomyosarcoma
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
Contributed by Christopher Dall, M.D. and Debra L. Zynger, M.D.
Rhabdomyosarcoma in
metastatic testicular
germ cell tumor
Chondrosarcoma in metastatic testicular germ cell tumor
Primitive 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
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
- Teratoma with somatic type malignancy most commonly contains which histologic type?
- Adenocarcinoma
- Primitive neuroectodermal tumor
- Rhabdomyosarcoma
- Sarcoma, not otherwise specified
- Squamous cell carcinoma
Board review style answer #1
Board review style question #2
- Which genetic feature would be most commonly found in teratoma with somatic type malignancy?
- Isochromosome 12p
- MYC amplification
- TERT promoter mutation
- Upregulation of ERG
Board review style answer #2
