Paranasal Sinus Embryonal Rhabdomyosarcoma Metastasizing to Breast and Ovary on PET/CT—A Case Report with the Review of Literature

Abstract Rhabdomyosarcoma (RMS) is a malignant soft tissue tumor of skeletal muscle origin. The head and neck, urinary tract, and extremities are the common sites of origin. Embryonal, alveolar, pleomorphic, and spindle/sclerosing are subtypes. It is more common in childhood and rare among adults. The incidence and risk factors for this disease are mainly largely unknown. RMS is sporadic in most instances; however, it is attributed to familial syndromes in some situations—its metastasis to the lungs, bone marrow, and lymph nodes. Breast and ovary involvement is scarce. Diagnostic workup mainly includes contrast-enhanced computed tomography (CECT) and magnetic resonance imaging (MRI). However, 18 F-fluro-deoxyglucose positron emission tomography ( 18 F-FDG-PET/CT) and PET/MRI are increasing contribution to providing functional insights about tumor biology and improving the diagnostic accuracy of the imaging workup. This report presents a case of the neck's embryonal RMS metastasizing simultaneously to the breast and ovary. PET/CT imaging revealed the unusual pattern, further validated by histopathology.