Incisional and excisional biopsy

The histologic diagnosis of this biopsy was rendered by the pathologists at Harborview Medical Center, Seattle, WA.  The histologic examination reveals a highly cellular and vascular neoplasm arranged in small nodules (Fig 3) in some areas and in a haphazard manner in others.  It is made up of interlacing fascicles of monomorphic spindle cells with mild cellular and nuclear atypia (Fig 4).  The mitotic activity is noticeable and frequent (Fig 4).  These cells are arranged around slit-like vascular spaces, some with erythrocytes.  This neoplasm is extensively positive with CD34 (Fig 5) and HHV8 antibodies (Fig 6). 

Figure 3. Low power (x20) histology shows a nodular appearance of the neoplasm.  This screening magnification clearly demonstrates the high cellularity of this neoplasm. 

 

Figure 4. Higher power (x200) histology shows the interlacing fascicles of spindle cell with mild atypia surrounding slit-like arrangement of blood vessels, some with erythrocytes.  Note the frequent mitotic activity. 

 

Figure 5. Figure 5 Low power (x100) Immunohistochemistry stain with CD34.  Note the strong positive spindle cells components as well as the small blood vessels.   

Figure 6. Figure 6 Low power (x100) Immunohistochemistry stain with HHV8.  Note the strong positive staining of the tumor cells.