Two reported cases of primary bone PH showed cystic spaces containing necrotic debris and lined focally by hobnailed epithelioid cells; those spaces were thought to be formed by discohesive tumor cells and no true vascular channels
Microscopic examination revealed multiple dilated vascular channels
of variable sizes, lined by a single layer of flattened endothelial cells most of which contained RBCs in their lumina (Fig.
Few areas showed well-formed closely-packed vascular channels
lined by atypical endothelial cells (Figure 1-2).
During fetal life, this vascular channel
causes the majority of blood to bypass the lungs (pulmonary circulation) of the fetus.
Transungual surgical approach revealed shiny encapsulated tumour, which was excised en bloc and biopsy confirmed glomus tumour (Figure 3, 4) section showing tumour composed of variable sized vascular channels
surrounded by cells with abundant eosinophilic cytoplasm and monomorphic nuclei (H&E, 100X).
Histologically, cavernous hemangiomas appear as closely packed, dilated vascular channels
lined with a layer of flattened endothelial cells.
(1) Vascular malformations are subclassified as either capillary, venous, lymphatic, or arterial according to the vascular channel
that predominates; some malformations involve a combination of vessels (e.g., lymphovenous and arteriovenous).
The other theory was published in 1950 by Arey, who wrote that the canal is a remnant of a vascular channel
formed during osteogenesis.
The structures are frequently dysmorphic, meaning that each vascular channel
has variably thick and thin muscle walls.
Prominent lymphatic or vascular channel
formation and dilation, as frequently noted in PT associated with emphysema, were not impressive in our cases.
Dilated vascular channel
in mid-dermal zone filled with RBCs.
Major Differential Diagnosis of Metastatic Angiosarcoma Metastatic Epithelioid Angiosarcoma Hemangioendothelioma Clinical features Young men Women Morphologic Lymphangitic or endovas- Bland neoplastic cells features cular growth pattern in chondroid or or neoplastic cells, myxoid stroma with vascular channel
formation CD31-factor VIII Positive Positive immunostains Kaposi Sarcoma Metaplastic Carcinoma Clinical features Acquired immunodeficien- Smokers, fifth to sixth cy syndrome decade Morphologic Malignant proliferation Pseudovascular channel features without anastomosing formation in a vascular spaces; pres- lymphangitic growth ence of intracyto- pattern plasmic and extracyto- plasmic eosinophilic bodies and extravasa- ted red cells CD31-factor VIII Positive Negative immunostains