Figure 5.

Histopathology of kaposiform lymphangiomatosis lesions. A) Lung with marked dilated lymphatic channels in pleura and interlobular septa. B) Lung with cluster of spindled cells and interspersed erythrocytes. C) Single, dilated lymphatic channel in reticular dermis and small cellular cluster in middle of the field. D) Dermal cellular cluster of hemosiderotic spindled cells with interspersed erythrocytes. E) Cytoplasmic immunopositivity for D2–40 in spindled cell cluster and adjacent dilated lymphatic vessels in lung. F) Nuclear immunopositivity for PROX1 in splenic sinusoidal lining cells. Dermal spindled cell clusters with cytoplasmic immunopositivity for D2–40 (G) and LYVE1 (H), and nuclear immunopositivity for PROX1 (I). J) Spleen with markedly expanded cords of Billroth and dilated sinusoids. K) Splenic hyperplastic sinusoidal cells, some with phagocytosed red blood cells and cytoplasmic eosinophilic globules.