Secondary involvement of lymph nodes in Kaposi sarcoma.

Kaposi sarcoma is a low-grade neoplasm first described by Moricz Kaposi in 1872. Although many attempts have been made to explain its pathogenesis, its etiology still remains obscure. In this regard, many aspects of the disease's genetic, epidemiological and histopathological backgrounds are even today unclear. We present the case of a 57-year-old male patient, constant HIV negative, with a history of plaque-like lesions on his right foot approximately two years ago. Following surgical removal, a diagnosis of Kaposi sarcoma, plaque stage was settled. One year after, the patient was admitted to the hospital for pain in the right ankle and foot, associated to paresthesis and trophic lesions at this level. Similar lesions developed in the popliteal fossa. Biopsy and subsequent histological and immunohistochemical examination revealed a KS at that level. The most recent hospital admission revealed the appearance of an indolent lymphadenopathy in the groin. Our case represents a rare occurrence of Kaposi sarcoma at a HIV-negative patient, which, after several local recurrences and progressive behavior, produced a lymph node involvement at the groin level. The immunohistochemical assessments have confirmed the diagnosis.