Fig. 1.

a-b: Clinical manifestation of the patient. Multiple exophytic, round, compressible bluish-purple nodules. Figure 1b, arrow: subtotal resection site of the feet SCH lesions. c-d: Radiography revealed multiple enchondromas at bilateral phalanges (Fig. 1c) and the left distal ulna (Fig. 1d). e-f: Histological analysis showed that the tumor consisted of bland spindle cell proliferations (Fig. 1e) and dilated, slit-like, thin-walled veins involving the superficial and deep layers of the dermis (Fig. 1f), confirming the diagnosis of SCH (hematoxylin–eosin). g-h: IGV visualization of NGS data for the SCH tissue (Fig. 1g) and cystic blood (Fig. 1h) with somatic mutation in IDH1 p.Arg132Cys