Moritz Kaposi

Close up of Kaposi's sarcoma on the sole of the feet & toes.

Nodular stage

Characteristic purplish hue is seen in multifocal Kaposi's of the palate and gingiva.

Numerous violet papules & nodules grouped in glans penis

Visceral involvement with Kaposi's sarcoma in AIDS is common. Here are multiple reddish

nodules seen over the gastric mucosa.

Patch-stage lesion with the characteristic "PROMONTORY" SIGN (blood vessel with plump

endothelial cells protruding into abnormal dilated vessels) indicated by the arrow.

Patch stage KS: slit-like vascular spaces in the dermis.

Plaque stage

Plaque stage KS: Large numbers of intracellular and extracellular eosinophilic hyaline globules

are visible. The arrows indicate so-called "AUTOLUMINATION", with paranuclear vacuoles

containing erythrocytes.

KS: characteristically has hyaline globules, as seen here stained with PAS.

KS: characteristically has deposits of hemosiderin granules and faint, pale pink

hyaline globules, as seen here.

KS: slit-like vascular spaces in the dermis of the skin with extravasation of RBCs.

The low power view of KS is cellular dermal nodule

Nodular KS

KS Schools of fish

Nodular KS: A. The dermis is expanded by a solid tumor nodule (H&E).

B. Fascicles of relatively monomorphic spindled cells, with slit-like vascular channels containing RBCs (H&E).

C. The nuclei of the tumor cells demonstrate immuno-reactivity for HHV-8 (LNA-1 immunohistochemical stain).

CD31

KS: immunohistochemical stain with antibody to CD34, which stains the

cells forming the vascular slits.

The antibody to HHV-8 latent nuclear antigen-1 (LNA-1)