A misleading frozen section in a lacrimal gland pleomorphic adenoma of a nine-year-old

Introduction: Benign pleomorphic adenomas of the lacrimal gland usually present as a painless, slow growing mass in healthy adults and rarely present in childhood. This report describes a pediatric patient found to have a lacrimal gland pleomorphic adenoma that mimicked rhabdomyosarcoma on frozen section. Report: A nine-year-old African American male presented with two months of unilateral proptosis and was found to have a left orbital mass on computed topography. Through a lateral orbitotomy, the mass was excised, but noted to appear distinct from the lacrimal gland. An intraoperative frozen section demonstrated a myxoid matrix with scattered cells mimicking rhabdomyoblasts. Because this sample lacked additional elements, the diagnosis of rhabdomyosarcoma could not be excluded, especially considering the patient's age, short time course of symptoms, and the tumor's intraoperative appearance. Permanent sections of the whole lesion provided definitive diagnosis. Conclusions: In the rare pediatric presentations, pleomorphic adenomas of the lacrimal gland can be difficult to quickly and definitively differentiate from a rhabdomyosarcoma. The unusual age of presentation and the misleading frozen section appearance in this case demonstrate the intricacies of managing pediatric orbital tumors and highlight the importance of permanent sections for definitive diagnosis.