Mediastinum
Other malignancies
Hemangioendothelioma

Author: Hanni Gulwani, M.D. (see Authors page)

Revised: 21 June 2018, last major update December 2012

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Hemangioendothelioma mediastinum

Table of Contents
Epithelioid | Kaposiform
Cite this page: Gulwani, H. Hemangioendothelioma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/mediastinumhemangioendo.html. Accessed July 19th, 2018.
Epithelioid
Poor prognostic factors
Case reports
Gross description
  • Circumscribed but unencapsulated mass, associated with adventitia of large blood vessels
  • Has glistening and hemorrhagic cut surface

Microscopic (histologic) description
  • Cords or disorganized sheets of markedly vacuolated polygonal cells in myxohyaline stroma
  • Variable nuclear atypia
  • Variable mitotic activity

Microscopic (histologic) images

Images hosted on other servers:

Various stains

Histologic sections of a tumor



Positive stains
Negative stains
Electron microscopy description
  • Weibel-Palade bodies

Differential diagnosis
Kaposiform
Definition / general
  • Rare pediatric neoplasm

Sites
  • Usually in soft tissue of retroperitoneum and extremities

Clinical features
  • May be locally invasive but distant metastases are rare
  • Associated with Kasabach-Merritt syndrome, a consumptive coagulopathy associated with vascular lesions
  • Not associated with Kaposi sarcoma or human herpesvirus 8

Case reports
Treatment
  • Aggressive chemotherapy may be helpful

Microscopic (histologic) description
  • Diffusely infiltrative, vascular, spindled tumor infiltrating lobules of thymus, which may be depleted of lymphocytes
  • Resembles capillary hemangioma and Kaposi sarcoma
  • May have glomeruloid proliferations of epithelioid endothelial cells
  • Cells may have intracytoplasmic lumina with hyaline globules, hemosiderin deposition
  • Spindled cells have slitlike vascular spaces resembling Kaposi sarcoma
  • Frequent mitotic activity

Microscopic (histologic) images

Images hosted on other servers:

Spindled cells surround residual thymic structures

Glomeruloid nests with intracytoplasmic lumina

Tumor cells are keratin-, residual thymus is keratin+



Positive stains
Negative stains