Figure 1
Primary diagnosis.
(a, b) Abdominal CT. An irregular sclerotic lesion in hemicorpus L5, with extensive associated paravertebral soft tissue involvement (5.5 × 6.5 × 6.0 cm) (arrows).
(c, d) Spinal MRI. A T2‑hyperintense, heterogeneously contrast‑enhancing mass in hemicorpus L5, with associated soft tissue involvement extending into the intervertebral foramen L4‑L5 (arrow).
Figure 2
Splenic metastasis.
(a, b) Abdominal CT. A sharply defined mass (5.5 × 7.2 × 5.8 cm), globally hypodense and inhomogeneously contrast‑enhancing, located cranially and subcapsular in the spleen. Notice the bulging of the diaphragm (arrows), without signs of pleural/pulmonary invasion.
(c, d) Abdominal US. A sharply defined, heterogeneous mass (5.5 × 7.2 cm) located cranially and subcapsular in the spleen. Colour Doppler shows present yet not pronounced vascularization.
Figure 3
Macroscopic pathological examination of the spleen.
Figure 4
Microscopic pathological examination of the spleen.
(a, b) Haematoxylin and eosin staining of a splenectomy specimen. The splenic tissue is diffusely invaded by small round blue cells and necrosis. Notice the fibrotic islands with surrounding characteristic cells.
(c) Immunohistochemical staining of the splenectomy specimen. Strong, diffuse positivity for CD99 in a honeycomb pattern, correlating with high membranous expression typical for Ewing sarcoma.