The document provides a detailed overview of Kaposi's sarcoma, highlighting various clinical and histopathological features, including the appearance of lesions and nodules in different stages of the disease. It describes characteristics such as purplish hues, visceral involvement in AIDS patients, and the presence of hyaline globules and hemosiderin granules. Immunohistochemical staining techniques are mentioned for identifying tumor cells and vascular structures associated with the condition.

6. Moritz Kaposi

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

19. Nodular stage

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

31. Numerous violet papules & nodules grouped in
glans penis

35. Visceral involvement with Kaposi's sarcoma in
AIDS is common. Here are multiple reddish
nodules seen over the gastric mucosa.

69. Patch-stage lesion with the characteristic
"PROMONTORY" SIGN (blood vessel with plump
endothelial cells protruding into abnormal
dilated vessels) indicated by the arrow.

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

73. Plaque stage

74. 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.

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

76. KS: characteristically has deposits of
hemosiderin granules and faint, pale pink
hyaline globules, as seen here.

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

78. The low power view of KS is  cellular dermal
nodule

79. Nodular KS

81. KS  Schools of fish

82. 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).

95. CD31

96. KS: immunohistochemical
stain with antibody to
CD34, which stains the
cells forming the vascular
slits.

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