Epithelioid Hemangioendothelioma

 Multicentricity at presentation likely represents locoregional metastases



• Treatment: Wide surgical excision with negative margins

• Indolent clinical course in majority of cases

• Metastases in 20-30%

• Overall mortality rate of 10-20%
image High-risk EHE features size > 3 cm and > 3 mitoses/50 HPF
– Associated with significant decrease in survival




Microscopic




• Infiltrative growth with absence of defined lobularity
• Epithelioid eosinophilic cells arranged in cords, nests

image Intracytoplasmic vacuoles common (blister cells)

• Well-formed vascular channels typically absent

• Characteristic myxoid to hyaline stromal matrix

• Involvement of larger vessels common


Ancillary Tests




• CD31(+), CD34(+), ERG(+), FLI-1(+)
• Nuclear TFE3(+) observed in distinctive genetic subset

• Keratin (+) in up to 35% of cases, often focal

• Molecular: t(1;3)(p36;q25) with WWTR1CAMTA1

image Distinctive subset contains YAP1TFE3 fusion


Top Differential Diagnoses




• Epithelioid hemangioma

• Epithelioid angiosarcoma

• Epithelioid sarcoma

• Myoepithelioma of soft tissue

image
Epithelioid Hemangioendothelioma: Clinical Photo
Clinical photograph shows a rare cutaneous epithelioid hemangioendothelioma (EHE) presenting as an exophytic lesion.


image
Epithelioid Hemangioendothelioma
EHE is a distinctive malignant vascular neoplasm characterized predominantly by cords of epithelioid tumor cells within a characteristic myxoid to hyaline matrix.

image
EHE With Involvement of Larger Vessel
EHE is an angiocentric neoplasm and evidence of origin from a larger vessel may be evident histologically. Note the residual smooth muscle wall image in this image. Tumor cells often extend outward from the involved vessel into the surrounding tissues.

image
CD31 Expression by Immunohistochemistry
EHE shows expression of endothelial markers, including CD31 (shown), CD34, ERG, and FLI-1. Focal keratin positivity is seen in up to 1/3 of cases.


TERMINOLOGY


Abbreviations




• Epithelioid hemangioendothelioma (EHE)


Synonyms




• Intravascular bronchioloalveolar tumor (lung)


Definitions




• Malignant angiocentric vascular neoplasm composed of epithelioid endothelial cells within characteristic myxohyaline stromal matrix


CLINICAL ISSUES


Epidemiology




• Incidence
image Rare tumors

• Age
image Wide age range affected
– Most common in 30- to 50-year-old patients

– Rare in childhood

• Sex
image Slight female predominance


Site




• Wide distribution in soft tissue
image Extremities, head/neck region, others

• Visceral organs (particularly liver and lung)


Presentation




• Solitary, often painful mass
image Superficial or deep

image Rarely cutaneous

• Apparent multicentricity at time of presentation (up to 50% of cases)
image Recent molecular data supports conclusion of locoregional metastases over multiple primary lesions

• Occlusion of vessels
image 30-50% of cases arise in or are associated with preexisting vessel

image May cause more profound vasoocclusive symptoms, including edema


Treatment




• Wide surgical excision with negative margins

• No proven role for adjuvant chemotherapy &/or radiotherapy


Prognosis




• Indolent clinical course in majority of cases
image Local recurrence in 10-15%

• Metastases in 20-30%
image Usually to liver, bone, lungs

image Occasionally regional lymph nodes

• Overall mortality rate of 10-20%

• Proposed risk assessment
image High-risk EHE features size > 3 cm and > 3 mitoses per 50 HPF
– Significant decrease in survival in these cases


MACROSCOPIC


General Features




• Well-circumscribed nodular lesion

• Firm, tan-gray cut surface

• Intravascular tumors may simulate organizing thrombi


Size




• Wide size range
image Mean: 2.5 cm in 1 large series


MICROSCOPIC


Histologic Features




• Infiltrative growth with absence of defined lobularity
• Epithelioid cells arranged in cords, singly, and in small aggregates or nests

image Pale to densely eosinophilic cytoplasm

– Intracytoplasmic vacuoles representing primitive vascular lumina (so-called blister cells)

image May contain erythrocytes

image Small, vesicular nuclei ± small nucleoli

– Occasional tumors show marked nuclear pleomorphism and hyperchromasia

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

Apr 24, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Epithelioid Hemangioendothelioma
Premium Wordpress Themes by UFO Themes
%d bloggers like this: