Keywords: Pulmonary epitheloid hemangioendothelioma; vascular endothelial growth factor-A (VEGF-A), weibelpalade body
Pulmonary epithelioid hemangioma (PEH) comprises
about 12% of all epithelioid hemangioendothelioma.[
The clinical behavior of PEH ranges from well-differentiated hemangioma to high-grade angiosarcoma. The clinical spectrum of the disease varies from silent to an aggressive disease with widespread metastasis.
More than half of the patients are asymptomatic that
mostly diagnosed incidentally. Coughing, shortness of
breath, pleuritic chest pain and/or hemoptysis is some
of the possible respiratory symptoms.[
For the diagnosis, a good histopathological evaluation
of the biopsy is required. It is like a hesitation
at the primitive stage of vascular differentiation, with
undeveloped vascular spaces from endothelial cells
in epithelioid or histiocytoid appearance. It should
be differentiated from various sarcomas with epithelioid
appearance. The other differential diagnoses are
melanomas and metastatic carcinomas. Electron microscopic
evaluation and immunohistochemical evaluation
is useful for the diagnosis. Electron microscopy
shows a well-developed basal lamina, picnotic vesicles,
and more specific Weibel-Palade bodies. Immunohistochemically,
Factor VIII and CD31 antigens are positive
in tumor cells of PEH. To understand if the tumor
is vascular in origin, CD34 is useful, as this antigen is
a sensitive marker of vascular tumors. The other auxiliary
markers, HMB-45 and melanin, can be used for
the diagnosis of melanoma. Mitotic activity and nuclear
atypia are expected to be higher in carcinoma,
melanoma and epithelioid angiosarcoma than in PEH.
Necrosis is common and vascular differentiation occurs
as the formation of irregular sinusoidal vascular
channels in epithelioid angiosarcoma. Sometimes, increased
mitotic activity (more than one mitosis at 10
magnification), focal spindle cells and necrosis are
present in PEH. In these cases, PEH exhibits more aggressive
behavior.
Depending on the rarity of the disease, there is no
standardization in treatment. Wide local excision with
possible regional lymph node dissection is recommended
for the resectable ones. The mean five-year
survival is about 60% after surgical excision.[13] As the
rates of local recurrence are about 10-15%, some studies
recommend radiotherapy fallowing surgery, especially
for the ones in bones. However, radiotherapy alone is
not appropriate as it is not effective in slow-growing
tumors. Surgery can be possible in only cases with unilateral
disease with single and/or multiple nodules. If it
is bilateral, surgery is impossible and in that situation,
chemotherapy can be used with unclear benefits. Till now, Interferon-?, Carboplatin, Paclitaxel and Bevacizumab
have been tried.[
Informed consent: Written informed consent was obtained from the patient for the publication of the case report.
Peer-review: Externally peer-reviewed.
Conflict of Interest: No conflict of interest to declare.
Financial Disclosure: No funding was received.
Authorship contributions: Concept - H.D., Ö.Ö., İ.Ö.; Design - H.D.; Supervision - H.D., Ö.Ö., İ.Ö.; Materials - H.D., İ.Ö.; Data collection &/or processing - H.D.; Analysis and/ or interpretation - H.D., Ö.Ö., İ.Ö.; Literature search - H.D.; Writing - H.D.; Critical review - H.D., Ö.Ö., İ.Ö.