NCI Definition: A neoplasm arising from the epithelial cells of the thymus. Although thymomas are usually encapsulated tumors, they may invade the capsule and infiltrate the surrounding tissues or even metastasize to distant anatomic sites. The following morphologic subtypes are currently recognized: type A, type B, type AB, metaplastic, micronodular, microscopic, and sclerosing thymoma. Thymomas type B are further subdivided into types B1, B2, and B3. Thymoma type B3 usually has the most aggressive clinical course. [1]

Thymomas most frequently harbor alterations in TP53, DNMT3A, WRN, SETD2, and PDGFRA [2].

Most Commonly Altered Genes in Thymoma

TP53 c.217-c.1178 Missense, TP53 Mutation, TP53 Missense, TP53 Exon 5 Mutation, and WRN Mutation are the most common alterations in thymoma [2].

Top Alterations in Thymoma

Significant Genes in Thymoma


Disease Details

THYMOMA, UNDETERMINED, Thymus thymoma (NOS), Thyoma
Thymic Epithelial Neoplasm
Thymoma Type A, Invasive Thymoma, Encapsulated Thymoma, Thymoma Type AB, Malignant Thymoma, and Thymoma Type B
OncoTree Name
OncoTree Code


1. National Cancer Institute. NCI Thesaurus Version 18.11d. https://ncit.nci.nih.gov/ncitbrowser/ [2018-08-28]. [2018-09-21].

2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 8. This dataset does not represent the totality of the genetic landscape; see paper for more information.

3. All assertions and clinical trial landscape data are curated from primary sources. You can read more about the curation process here.