Pediatric synovial sarcoma in the retropharyngeal space: a rare and unusual presentation

Abstract

Synovial sarcomas in the head and neck are extremely rare tumors, especially in the pediatric population. 3-5% of synovial sarcomas occur in the head and neck region displaying varied imaging and histopathological features resulting in frequent misdiagnosis. These tumors have a poor prognosis; hence early diagnosis and accurate classification based on imaging, histopathology, and immunohistochemistry are critical for prompt treatment. To the best of our knowledge, imaging findings of pediatric retropharyngeal lipomatous synovial sarcoma have not been reported to date in English medical literature. We report, for the first time, a rare case of retropharyngeal lipomatous synovial sarcoma in a ten-year-old child and discuss the case-specific imaging findings in our patient using magnetic resonance imaging and computed tomography.

Figure 1

T1W axial (a), STIR axial ((b), (c)), and coronal (d) images showing a large complex signal retropharyngeal mass with a large lipomatous component (asterisk) and multiple fluid-fluid levels (white arrows) and scattered cystic components (block arrows). Postcontrast fat saturated axial (e) and sagittal (f) images reveal dense heterogeneous enhancement within the soft tissue component of the mass (black arrows).

Figure 2

Immunohistochemistry and histopathological sections reveal tumor cells positive for bc12 (a) and focally positive for EMA (b), and the tissue shows polygonal to spindle shaped cells arranged in whorls and storiform pattern ((c), (d)) on haematoxylin and eosin staining.