DOI: https://doi.org/10.36347/sjmcr.2026.v14i03.015

Pages: 385-389

Rhabdomyosarcoma (RMS) of the lacrimal sac is an extremely rare and aggressive malignancy arising from mesenchymal cells with skeletal muscle differentiation. While RMS is the most frequent soft tissue sarcoma in children, its manifestation in the lacrimal sac is exceptional and may mimic benign inflammatory conditions, leading to delayed diagnosis and treatment. We report the case of a 45-year-old woman with a rapidly enlarging medial canthal mass, found to be embryonal RMS with orbital and intracranial extension. Diagnosis was confirmed by histopathology and immunohistochemistry. She underwent extensive surgery followed by VAC-IE chemotherapy with good tolerance. Although exceedingly rare, rhabdomyosarcoma of the lacrimal sac should be considered in the differential diagnosis of rapidly progressive orbital masses. This case highlights the rarity and aggressiveness of adult-onset rhabdomyosarcoma of the lacrimal sac, its challenging differential diagnosis, and the importance of a multidisciplinary approach in both diagnosis and management.