Epithelioid Hemangioendothelioma

 Nuclear staining with CAMTA1 immunohistochemistry



• Tumors with YAP1-TFE3
image Well-formed vascular channels, tumor cells with voluminous eosinophilic cytoplasm

image Nuclear staining with TFE3 immunohistochemistry




Top Differential Diagnoses




• Dense myxoid stroma and intracytoplasmic vacuoles can mimic adenocarcinoma

• Greater nuclear atypia, mitotic activity, and destructive growth pattern distinguish angiosarcoma from epithelioid hemangioendothelioma

image
Central Hypocellular Zone
Central portion is typically hypocellular with loosely arranged spindle cells in a fibromyxoid or sclerotic stroma. The findings can simulate a scar or sclerosed hemangioma.


image
Poorly Formed Vascular Lumina
Poorly formed vascular lumina image and infiltrating tumor cells in a fibromyxoid stroma image can mimic cholangiocarcinoma.

image
Intracytoplasmic Lumina
Cellular area with epithelioid tumor cells image in a fibromyxoid stroma demonstrates mild nuclear atypia with no mitoses. Vascular differentiation is seen in the form of intracytoplasmic lumina with red blood cells image .

image
CD31 Staining
CD31 is strongly expressed in tumor cells, highlighting the characteristic infiltrative pattern with entrapment of portal tracts image and extension along the sinusoids in adjacent liver.


TERMINOLOGY


Abbreviations




• Epithelioid hemangioendothelioma (EHE)


Definitions




• Uncommon, considered low-grade malignancy


ETIOLOGY/PATHOGENESIS


Molecular Changes




• t(1;3) resulting in WWTR1-CAMTA1 fusion protein in > 80%

• YAP1-TFE3 fusion in small subset


CLINICAL ISSUES


Presentation




• Primarily affects adults (30-40 years)
image Rare in children

• Slightly more common in women

• Upper abdominal mass or discomfort and elevated alkaline phosphatase may be present
image Often discovered as incidental finding


Treatment




• Primary treatment is hepatic resection
• Liver transplantation in unresectable cases

image Extrahepatic spread not contraindication for transplant

Only gold members can continue reading. Log In or Register to continue

Related posts:

  1. Neonatal Hemochromatosis
  2. Hepatoportal Sclerosis
  3. Drug-Related Acute Hepatitis
  4. Biliary Atresia

Stay updated, free articles. Join our Telegram channel
Tags:
Apr 20, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Epithelioid Hemangioendothelioma

Full access? Get Clinical Tree
Get Clinical Tree app for offline access