Germ Cell Tumors of the Mediastinum / Thymus
Classification / Lists
Extragonadal Germ Cell Tumors (excluding CNS)
Age | Site | Histology | Comments |
---|---|---|---|
Congenital / Neonatal | Primarily sacrococcygeal, others midline | Teratoma with or without YST | Immaturity and histologic type not critical; may recur post resection but curable with chemotherapy |
Childhood (7 mo - puberty) | Various midline | Usually YST | Rare but frequently aggressive |
Adult | Cervical / thyroid / mediastinum / thymus | Mature teratoma | Benign |
Immature teratoma, YST, others | Potentially aggressive; mediastinal tumors may be associated with hematologic malignancy | ||
Sacrococcygeal | Mature Teratoma | Benign | |
Immature teratoma | Probably benign, has not been shown to be aggressive | ||
Other germ cell tumors | Rare, aggressive | ||
Retroperitoneum | Any type | Most should be considered metastases from gonadal primary |
Non-Thymic Neoplasms that May Arise Primarily in the Thymus
- Hematopoietic
- Primary mediastinal large B cell lymphoma
- Extranodal marginal zone lymphoma
- Precursor T lymphoblastic lymphoma/leukemia
- Hodgkin lymphoma
- Germ cell tumors
- Seminoma (Germinoma)
- Embryonal carcinoma
- Yolk sac tumor
- Teratoma
- Choriocarcinoma
- With associated somatic type malignancy
- Embryonal rhabdomyosarcoma
- Angiosarcoma
- Others
- With associated hematologic malignancy
- Acute myelogenous leukemia
- Acute megakaryoblastic leukemia
- Others
Miscellaneous Thymic Lesions and Conditions
- Atrophy
- Cysts
- Most are non-specific
- Neoplasms most commonly associated with cysts
- Castleman disease
- Dysplasia
- Hyperplasia
- B cell/lymphoid/germinal center
- Rebound
- True thymic
- Microscopic thymoma / nodular hyperplasia of thymic epithelium
- (Ectopic hamartomatous thymoma)
Intrinsic Tumors of the Thymus
- Thymoma
- Type A
- Type AB
- Type B1
- Type B2
- Type B3
- Other types
- Micronodular with lymphoid stroma
- Metaplastic
- Sclerosing
- With prominent signet ring like features
- Thymic carcinoma
- Low grade
- Well differentiated squamous
- Basaloid
- Adenocarcinoma
- Adenosquamous
- Low grade mucoepidermoid
- Micronodular
- High grade
- Lymphoepithelial-like
- Large cell undifferentiated
- Clear cell
- Sarcomatoid
- Midline carcinoma with t(15;19)
- Low grade
- Thymic neuroendocrine carcinoma
- Well differentiated (carcinoid)
- Poorly differentiated
- Small cell
- Large cell
- Miscellaneous