2. Vascular neoplasms can be endothelium-derived (e.g., hemangioma, lymphangioma,
angiosarcoma) or arise from cells that support and/or surround blood vessels (e.g.,
glomus tumor, hemangiopericytoma).
Although a benign, welldifferentiated hemangioma can turn to anaplastic high-grade
angiosarcoma
The endothelial derivation of neoplasms that do not form distinct vascular lumens can
usually be confirmed by immunohistochemical demonstration of endothelial cell–
specific markers such as CD31
3. the distinction between benign and malignant can occasionally be difficult.
Two general rules of thumb are as follows:
Benign tumors usually produce obvious vascular channels filled with
blood cells or lymph, lined by a layer of normal-appearing endothelial
cells.
Malignant tumors are more cellular, show cytologic atypia, and are
proliferative, including mitotic figures; they usually do not form well-
organized vessels.
4.
5. BENIGN TUMORS AND TUMOR-LIKE CONDITIONS
Hemangioma
very common tumors
characterized by increased numbers of normal or abnormal vessels filled with blood
constitute 7% of all benign tumors of infancy and childhood;
most are present from birth and expand along with the growth of the child.
6. many of the capillary lesions regress spontaneously.
some hemangiomas can involve large portions of the body (angiomatosis),
most are localized.
The majority are superficial lesions, often of the head or neck, but they can
occur internally, mostly in the liver.
Malignant transformation occurs rarely
There are several histologic and clinical variants
7. CAPILLARY HEMANGIOMA.
The most common variant
Site: skin, subcutaneous tissues, and mucous membranes of the oral cavities
and lips also in liver, spleen, and kidneys.
The “strawberry type” or juvenile hemangioma of the skin of newborns is
extremely common and may be multiple.
Age: grows rapidly in the first few months but then fades at 1 to 3 years of
age and completely regresses by age 7 in 75% to 90% of cases.
8. MORPHOLOGY.
Grossly:
Color: bright red to blue
Size: vary from a few millimeters to several centimeters in diameter
can be level with the surface of the skin or slightly elevated,
an intact overlying epithelium
9. Histologically,
unencapsulated aggregates of closely packed, thin-walled capillaries,
usually blood-filled and lined by flattened endothelium;
vessels are separated by scant connective tissue stroma.
The lumens may be partially or completely thrombosed and organized.
Vessel rupture accounts for hemosiderin pigment in these lesions as well as focal
scarring.
10. CAPILLARY HEMANGIOMA
A , H E M A N G I O M A O F T H E
T O N G U E .
H I S T O L O G I C
A P P E A R A N C E O F ( B )
J U V E N I L E C A P I L L A R Y
H E M A N G I O M A
11. CAVERNOUS HEMANGIOMA.
Since they may be locally destructive and show no spontaneous tendency to regress, some
may require surgery.
tumors are of little clinical significance; except for a cosmetic disturbance and are vulnerable
to traumatic ulceration and bleeding.
visceral hemangiomas detected by imaging studies may have to be distinguished from more
ominous (e.g., malignant) lesions.
Brain hemangiomas are most problematic, because they can cause pressure symptoms or
rupture.
Cavernous hemangiomas are a component of von Hippel-Lindau disease
12. MORPHOLOGY
grossly:
are less well circumscribed and more frequently involve deep structures than capillary
hemangiomas
red-blue, soft, spongy masses
1 to 2 cm in diameter
rare giant forms can affect large subcutaneous areas of the face, extremities, or other
body regions.
13. Histologically,
the mass is sharply defined but not encapsulated
composed of large, cavernous blood-filled vascular spaces, separated by a
modest connective tissue stroma
Intravascular thrombosis with associated dystrophic calcification is common.
15. PYOGENIC GRANULOMA.
form of capillary hemangioma
it bleeds easily and is often ulcerated
Roughly a third of the lesions develop after trauma
Pregnancy tumor (granuloma gravidarum) is a pyogenic granuloma that occurs
infrequently (1% of patients) in the gingiva of pregnant women.
These lesions can spontaneously regress (e.g., after pregnancy) or undergo fibrosis;
in some cases surgical excision is required.
Recurrence is rare
17. Microscopic picture:
Well circumscribed with a lobular architecture
Characterized by small, arborizing vascular channels and bland endothelium
extensive edema and an acute and chronic inflammatory infiltrate
18. LYMPHANGIOMAS
THE BENIGN LYMPHATIC ANALOGUES OF BLOOD VESSEL HEMANGIOMAS.
S I M P L E ( C A P I L L A R Y )
L Y M P H A N G I O M A .
occurring in the head,
neck, and axillary
subcutaneous tissues.
slightly elevated or
sometimes
pedunculated lesions
up to 1 to 2 cm in
diameter.
Histologically, networks of
endothelium-lined small
spaces that can be
distinguished from
capillary channels only
by the absence of
C A V E R N O U S L Y M P H A N G I O M A
( C Y S T I C H Y G R O M A ) .
typically found in the neck or axilla
of children
rarely occur in the retroperitoneum
cavernous lymphangiomas of the
neck are common in Turner
syndrome
Cavernous lymphangiomas can
occasionally be (up to 15 cm in
diameter)
Histologically: composed of
massively dilated lymphatic
spaces lined by endothelial cells
and separated by intervening
connective tissue stroma
containing lymphoid aggregates.
The lesions are not
encapsulated, making definitive
19. GLOMUS TUMOR
Tumor differentiates toward modified smooth muscle of the glomus body
Age: young adults
Site: distal extremities, especially fingers and toes; deep or visceral tumors are rare
Red and blue subcutaneous nodule that is painful
may be multifocal
Grossly: Typically smaller than 1 cm; well-circumscribed dermal or subcutaneous
nodule
20. MICROSCOPIC PICTURE
Sheets or nests of uniform,
round cells with oval
nuclei and pale
eosinophilic cytoplasm
Groups of glomus cells
may surround dilated
vessels (glomangioma)
Minimal mitotic activity
May show focal
degenerative nuclear
atypia
21. BEHAVIOR
Glomus tumor is benign and typically treated by excision
about 5% to 10% recur
Malignant glomus tumors (glomangiosarcoma) are exceedingly rare; they
are typically large, in deep or visceral locations, with infiltrative growth,
nuclear atypia, and brisk mitotic activity
23. KAPOSI SARCOMA
Four forms (based primarily on population demographics and risks), all share the same underlying viral
pathogenesis:
Chronic KS (also called classic or European KS)
occurs in older men of Eastern European (especially Ashkenazi Jews) or Mediterranean descent.
associated with an underlying second malignancy or altered immunity,
it is not associated with human immunodeficiency virus (HIV).
presents with: multiple red to purple skin plaques or nodules, usually in the distal lower extremities; these
slowly increase in size and number and spread more proximally.
Although locally persistent, the tumors are typically asymptomatic and remain localized to the skin and
subcutaneous tissue.
24. Lymphadenopathic KS (also called African or endemic KS)
same general geographic distribution as Burkitt lymphoma mainly among South African
Bantu children
it is also not associated with HIV.
Skin lesions are sparse, and patients present instead with lymphadenopathy due to KS
involvement;
the tumor occasionally involves the viscera and is extremely aggressive.
In combination with AIDS-associated KS, KS is now the most common tumor in central
Africa (50% of all tumors in men in some countries).
25. Transplant-associated KS
occurs in the setting of solid-organ transplantation with its attendant long-term
immunosuppression.
It tends to be aggressive (even fatal) with nodal, mucosal, and visceral
involvement; cutaneous lesions may be absent.
Lesions occasionally regress when immunosuppressive therapy is attenuated, but
at the risk of organ rejection.
26. AIDS-associated (epidemic) KS
was originally found in a third of AIDS patients, particularly male
homosexuals
with current regimens of antiretroviral therapy, KS incidence less than 1%
AIDS-associated KS can involve lymph nodes or viscera
disseminates widely early in the course of the disease.
Most patients eventually die of opportunistic infections rather than from KS.
27. PATHOGENESIS.
a previously unrecognized herpesvirus—human herpesvirus-8 (HHV-8) or KS-associated
herpesvirus (KSHV) was identified in a cutaneous KS lesion in an AIDS patient
it is transmitted sexually and by poorly understood nonsexual routes—perhaps
including saliva.
KSHV is accepted as a necessary requirement for KS development, but tumor
progression also requires a cofactor; HIV clearly can provide this,
KSHV induces a lytic as well as a latent infection in endothelial cells, both of which are
probably important in KS pathogenesis
28. Cytokines derived from HIV-infected T cells, or inflammatory cells recruited in response
to the lytic infection local proliferation and local VEGF production.
Viral protiens prevent apoptosis by viral production of p53 inhibitors.
In its early stages, only a few cells are infected; with time virtually all spindle cells of
late-stage lesions carry KSHV;
29. MORPHOLOGY.
three stages are recognized: patch, plaque, and nodule.
• Patches:
grossly: red to purple macules typically confined to the distal lower extremities
Histology shows only dilated irregular endothelial cell–lined vascular spaces with interspersed lymphocytes, plasma
cells, and macrophages (sometimes containing hemosiderin). The lesions can be difficult to distinguish from
granulation tissue.
• plaques:
Grossly: With time, lesions spread proximally and become larger, violaceous, raised
Histology: composed of dermal accumulations of dilated, jagged vascular channels lined and surrounded by plump
spindle cells. Scattered between the vascular channels are extravasated red cells, hemosiderin-laden
macrophages, and other mononuclear inflammatory cells.
30.
31. • nodules:
Eventually, lesions become nodular and more distinctly neoplastic.
Histology:
composed of sheets of plump, proliferating spindle cells
mostly in the dermis or subcutaneous tissues , with small vessels and slitlike spaces
containing red cells.
More marked hemorrhage, hemosiderin pigment, and mononuclear inflammation is present;
mitotic figures are common,
round, pink, cytoplasmic globules of uncertain nature.
The nodular stage often heralds nodal and visceral involvement, particularly in the African and
AIDS-associated variants
32. HISTOLOGIC APPEARANCE OF NODULAR FORM,
DEMONSTRATING SHEETS OF PLUMP, PROLIFERATING
SPINDLE CELLS.
33. CLINICAL FEATURES
The course of KS varies widely and is significantly affected by the clinical setting.
Most primary KSHV infections are asymptomatic.
Classic KS is—at least initially—largely restricted to the surface of the body, and
surgical resection is usually adequate for an excellent prognosis.
Radiation can be used for multiple lesions in a restricted area, and chemotherapy yields
satisfactory results for more disseminated disease.
34. Lymphadenopathic KS can also be treated with chemotherapy or radiation therapy with good
results.
In immunosuppression-associated KS, withdrawal of immunosuppression (perhaps with
adjunct chemotherapy or radiation therapy) is often effective.
For AIDS-associated KS, antiretroviral therapy for HIV is usually helpful, with or without
therapy targeted to the KS lesions.
IFN-α and angiogenesis inhibitors are variably effective
newer strategies aimed at specific intracellular kinase pathways or the downstream
mammalian target of rapamycin are showing promise
35. HEMANGIOENDOTHELIOMA
intermediate behavior between benign, well-differentiated hemangiomas and highly
malignant angiosarcomas
denotes a wide spectrum of vascular neoplasms :
Epithelioid : Occurs in any age group but is rare in children. Usually involves dermal
or subcutaneous tissues of extremities.
Kaposiform : in children, often in first year of life.
Retiform and (Dabska tumor): retiform is more common in adults, and Dabska tumor
is more common in children
36. Gross Pathology
Violaceous plaques or subcutaneous nodules; often multinodular
Infiltrative borders and gray to white variegated cut surfaces
Epithelioid hemangioendotheliomas associated with large vessels may
resemble organizing thrombi
37. Histopathology
❚ Epithelioid hemangioendothelioma
● Cords and nests of polygonal endothelial cells with eosinophilic cytoplasm and
oval nuclei
● Intracellular cytoplasmic lumens with intraluminal red blood cells
● Intramural growth into preexisting vessels with
perivascular extension of tumor
● Tumor cells typically have bland, round to oval nuclei but may show some
pleomorphism
• Background stroma is myxoid or hyalinized
● Typically low mitotic rate
38. BEHAVIOR AND PROGNOSIS
Hemangioendotheliomas have borderline biologic behavior with the ability to recur
but rare metastasis
epithelioid hemangioendotheliomas are the most aggressive of the group,
metastasizing in up to 33% of cases
Surgical excision is standard treatment
medical therapy may be indicated for unresectable lesions or to treat consumptive
coagulopathy
40. ANGIOSARCOMA
Rare tumor
Age: usually seen in adults
Sites: Predilection for skin and superficial soft tissue, breast, bone, liver, and
spleen; rare in deep soft tissue
May be associated with chronic lymphedema (typically postmastectomy), previous
therapeutic radiation, or arteriovenous fistulas in renal transplant recipients
Angiosarcomas of liver are associated with prior
exposure to Thorotrast: a radioactive contrast agent formerly used for radiologic
imaging
41. Gross Pathology
Cutaneous angiosarcomas present as an ill-defined, bruiselike lesion or
ulcerated hemorrhagic nodules, or plaques
Commonly large hemorrhagic, ill-defined masses with spongy quality and
blood-filled spaces
42. epithelioid or fusiform cells
with rudimentary
vascular differentiation;
pleomorphism, mitoses,
and widespread tissue
infiltration are common
Tumor cells in vascular
spaces may be
attenuated or plump with
hyperchromatic nuclei
Spindle cell areas may
resemble fibrosarcoma
or other spindle cell
tumors
HISTOPATHOLOGY
43. PROGNOSIS
Angiosarcomas are treated with radical surgery and radiation therapy
Frequent recurrence and distant metastasis, most commonly to lungs, lymph
nodes, and bone
Prognosis is related to size, multifocality, and ability to achieve a complete excision
Angiosarcomas are aggressive tumors with current 5-year survival rates
approaching 30%.
44. HEMANGIOPERICYTOMA
rare tumors
derived from pericytes—myofibroblast-like cells that are normally arranged around
capillaries and venules.
Grossly: slowly enlarging, painless masses at any anatomic site, but are most
common on the lower extremities (especially the thigh) and in the
retroperitoneum.
Microscopically: consist of numerous branching capillary channels and gaping
sinusoidal spaces enclosed within nests of spindle-shaped to round cells.
45. Special stains : CD34 and SMA positivity confirm that these cells are outside
the endothelial cell basement membrane and are therefore pericytes.
Prognosis: The tumors may recur after excision, and roughly half will
metastasize, usually hematogenously to lungs, bone, or liver
