Ectopic Hamartomatous Thymoma
Khin Thway, BSc, MBBS, FRCPath
Key Facts
Terminology
Rare benign tumor composed of spindle, epithelial, and adipose tissue elements that occurs mainly in lower neck region of adult men
Etiology/Pathogenesis
Suggested derivation from sequestered branchial epithelium
Microscopic Pathology
Typically circumscribed
Haphazard admixture of spindle cells, epithelial cells, and adipose tissue
Diffuse expression of cytokeratins, particularly of high molecular weight, in both spindle and epithelial components
Can also express CD34, α-smooth muscle actin, and CD10
 In this case of ectopic hamartomatous thymoma, the lesion is circumscribed, as is typical. The admixture of cellular elements  and mature adipose tissue  is discernible at low power. |
 All 3 components are illustrated in this example. Mature fat is intermixed with sheets of bland spindle cells, and epithelial elements are interspersed, here, as squamous islands  . |
TERMINOLOGY
Abbreviations
Ectopic hamartomatous thymoma (EHT)
Definitions
Rare benign tumor composed of spindle, epithelial, and adipose tissue elements that occurs mainly in lower neck region of adult men
ETIOLOGY/PATHOGENESIS
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
