Lymphangioma-like Kaposi sarcoma: clinical, pathological, and microvascular imaging correlation

Lymphangioma-like Kaposi sarcoma is a rare variant that may clinically mimic lymphatic or bullous lesions. We report the case of a 71-year-old immunocompetent man with progressive violaceous plaques, nodules, bullous-like lesions, and marked edema of the lower limbs. Histopathology showed spindle-cell proliferation with ectatic vascular spaces, and immunohistochemistry was positive for human herpesvirus 8 (HHV-8) confirming Kaposi sarcoma. Serological tests for human immunodeficiency virus and other infections were negative, and imaging studies showed no systemic involvement. High-frequency dermatologic ultrasound with superb microvascular imaging (SMI) demonstrated dermal anechoic and hypoechoic lymphatic-like structures with variable vascular flow. The patient received liposomal doxorubicin, with marked clinical improvement and complete resolution of edema. This case highlights an uncommon presentation of Kaposi sarcoma in an immunocompetent patient and suggests that high-frequency ultrasound may assist in lesion characterization and therapeutic follow-up.