Lymphangioma-like Kaposi sarcoma: case report

Area of Science:

• Dermatology
• Oncology
• Pathology

Background:

• Kaposi sarcoma (KS) is a multifocal vascular neoplasm with diverse clinical and histological presentations.
• The lymphangioma-like variant (LLKS) is exceptionally rare, comprising less than 5% of all KS cases.
• Understanding KS variants is crucial for accurate diagnosis and effective treatment strategies.

Observation:

• A 76-year-old, HIV-negative woman with a history of classic KS developed new bullous lesions on her lower extremities.
• Histopathological examination of the lesions revealed features of lymphangioma-like KS (LLKS) alongside areas of classic KS.
• Immunohistochemical staining for human herpesvirus 8 (HHV-8) was positive.

Findings:

• The diagnosis of LLKS was confirmed based on the characteristic histological findings of dilated, bizarre vascular channels and positive HHV-8 staining.
• LLKS presents with a unique morphology that can mimic other vascular tumors, emphasizing the need for careful diagnostic evaluation.
• The presence of both LLKS and classic KS areas in the same patient highlights the potential for morphologic diversity within KS.

Implications:

• Accurate diagnosis of LLKS is essential for appropriate management, with radiotherapy being a proposed treatment option in this case.
• Recognizing the clinical hallmark of "bulla-like" lesions associated with LLKS can aid in early identification.
• The lymphatic-like appearance of LLKS suggests potential insights into the histogenesis of Kaposi sarcoma.