Fig. 2

Planar bone scan (a, dorsal view) showed no hyperperfusion (not shown) but increased blood pool in the left iliac bone in the early images 5 min p.i. (above) and a moderately enhanced tracer uptake in the delayed phase images (bottom). In SPECT/CT images 2 h p.i. (transversal view in b, coronal view in c), the lesion is easily visible with an inhomogeneous tracer uptake, slightly accentuated in the peripheral zone. Histology (HE staining) revealed lamellar and woven bone with curvilinear and pseudopagetoid features, accompanied by a moderately cellular intertrabecular fibrous stroma (d, magnification 100x). In some areas, clusters of foamy histiocytes were present (e, magnification 200x)