Metastasis from scapular Ewing's sarcoma presenting as sutural diastasis: An unusual presentation

Abstract

Ewing's sarcoma is a malignant non-osteogenic primary tumor of the bone. It is one of the most common primary malignant tumors of bone. Peak incidence is noticed in second decade of life with male preponderance of 1.6:1. It occurs most frequently in long bones and flat bones of pelvic girdles. In 30% cases, Ewing's sarcoma is multicentric in origin. In 14-50%, multiple metastases are present at the time of diagnosis. CNS spread is rare and isolated CNS involvement is not seen. Skull metastasis of Ewing's sarcoma is not rare compared to primary Ewing's sarcoma of the skull, but the actual frequency is unknown. We wish to report a case of "Primary Ewing's sarcoma of scapula with metastasis to Skull Vault in a Child resulting in sutural diastasis" diagnosed by clinicoradiological examination and confirmed by histopathology.

Keywords: Ewing’s sarcoma; non-osteogenic; skull vault; sutural diastasis.

Figure 1

Clinical photograph showing massive scapular swelling

Figure 2

Clinical photograph showing skull vault swelling in the frontoparietal region

Figure 3

Pre-treatment radiograph of right shoulder showing a sclerotic lesion of scapula with loss of definition of margins of scapula and soft tissue mass

Figure 4

Lateral radiograph of skull vault showing an osteolytic lesion with erosion of inner and outer tables associated with sutural diastasis and periosteal reaction

Figure 5

FNAC from scapular mass was consistent with small round cell tumor of childhood – Ewing’s sarcoma. (a) Photomicrograph showing loose clusters and the discrete cell population of monomorphic, round cells with scant cytoplasm, slightly irregular nuclei, and occasional pseudo-rosette and focal necrosis. Note that a mixture of two types of cell population – small and large – can be appreciated, one of the criteria for diagnosis of Ewing’s sarcoma (H and E stain). (b) Photomicrograph focused to show rosette like structure formation, as occasionally seen in cases of Ewing’s sarcoma (H and E stain). (c) Photomicrograph showing PAS positivity in few viable cells (PAS stain)

Figure 6

Clinical photograph showing significantly reduced scapular swelling (post treatment)

Figure 7

Radiograph of right shoulder showing extensive sclerosis of the lesion after chemoradiation

Figure 8

Post-treatment lateral radiograph of skull vault showing sclerosis in and around the lesion. The sclerosis seems to be bridging the diastasis