[Malignant rhabdoid tumor of the maxillary sinus: a case report].

Malignant rhabdoid tumors(MRTs) are most commonly found in the kidneys of young children, and the prognosis is very poor.Here，we present a case of primary MRT of the maxillary sinus, which is an extremely rare and scarcely been reported.A 56-year-old male complained of repeated epistaxis for over 1 year duration.CT scan showed soft tissue density in the paranasal sinus,and no obvious bone resorption or damage was observed.The patient underwent endoscopic sinus surgery.Postoperative biopsy showed undifferentiated malignant neoplasm with features of rhabdoid differentiation. Immunohistochemistry(IHC) was positive for the expression of vimentin but negative for desmin, pan CK and S-100. Histopathological examination and IHC analysis supported the diagnosis of MRT..