A 62-year-old man presents to the emergency room with pain
and swelling in his left foot, which also has patches of discoloration
that have been present for three months. The pain and swelling,
however, have appeared only during the previous week. His
medical history is significant for rheumatoid arthritis and
hypertension, and his current medications include fosinopril
and atenolol. He also started cephalexin therapy three days
before this visit, as prescribed by his primary care physician.
Physical examination reveals a slightly swollen and tender
foot marked by purplish blotches and a nontender discolored
plaque on the sole.
Kaposi sarcoma is a low-grade vascular tumor
associated with human herpesvirus 8 infection. It is characterized
by lesions that develop beneath the skin or in the mucous membranes.
These lesions, which usually appear as raised blotches or nodules,
may be purple, brown, or red. Occasionally, Kaposi sarcoma may
also present as plaquelike lesions on the sole of the foot.
Although they are usually asymptomatic, these lesions can be
painful if they cause swelling of the surrounding skin. Biopsy
is the preferred diagnostic method. After this patient's diagnosis
of Kaposi sarcoma was established, he tested HIV-positive. Cryotherapy,
laser, and radiation therapy are effective in controlling local
tumor growth, as is intralesional chemotherapy with vinblastine
and topical 9-cis-retinoic acid.
Drs. Yalamanchili and Patel are residents in internal medicine
at Robert Packer Hospital in Sayre, Pennsylvania.
