Kaposi's sarcoma is a slowly progressive and rare vascular tumor usually occurring on
the lower extremities. It is characterized clinically by red-purple plaques and nodules.
The essential histologic features of Kaposi'a sarcoma include (1) proliferation of small
vessels with endothelial cells ; (2) proliferation of spindle shaped, somewhat pleomorphic
cells having dark prominent nuclei ; and (3) extravasation of erythrocytes and deposition
of hemosiderin pigments. Also, infiltration of chronic inflammatory cells including
lymphocytes, plasma cells, and large mononuclear cells is often present. 7 cases of
Kaposi's sarcoma have been reported in Korea.
Authors experienced a ease of Kaposi'a sarcoma in a 73 year old male who visited to
the C.A.U. hospital complaining with multiple painless bluish papules and nodules on
hands, legs, and feet for 3 years.
The submitted specimens were two bluish brown excional biopsies skin, measuring 2×
0.7×0.5 ㎝ and 1.5×0.6×0.6 ㎝. The epidermis of the larger one showed bluish nodular
elevation with smooth surface. Cut surface showed bluish and hemorrhagic areas which
were poorly delineated and located mainly in the dermis. Histologically, sections from
plague lesion of the right hand disclosed poorly demarcated and somewhat nodular areas
of variable sized vascular proliferation associated with spindle cell proliferation.
Hemosiderin pigments, extravasation of erythrocytes, and lymphocytic infiltration were
also noted. Fewmitoses of spindle cells were seen, but cellular atypism and
pleomorphism was rather mild. On reticulin staining, prominent vascular proliferation
wasnoted in both papillary and reticular dermis. On Gomori trichrome staining, reddish
endothelial cells were seen within the proliferated vascular channels. Also seen were
fibroblast-like spindle cell proliferation at the stroma.
Sections from bluish nodule of the right lower leg revealed moderate to marked
hyperkeratosis acanthosis, and dyskeratosis in the epidermis. Relatively nodular or
patchy proliferation of vascular components associated perivascular spindle cell
proliferation were noted at the whole layer of the epidermis, and even extended to
subcutaneous adipose tissue. A few mitoses of spindle cells, extravasation of
erythrocytes, and hemosiderin pigmentation were found along and near the proliferated
vascular channels. Reticulin staining and Gomori trichrome staining revealed the similar
histologic pattern as the above plaque lesion except more prominent nodular arrangement
of vascular channels.
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