Malignant Mixed Müllerian Tumor with Rhabdoid Features: A Report of Two Cases and a Review of the Literature

Rhabdoid tumors were originally described as a type of pediatric renal neoplasm that contains cells resembling rhabdomyoblasts but lacking muscle differentiation. Extrarenal rhabdoid tumors have since been reported in multiple anatomic sites in the pediatric and adult population. These tumors are characterized by an aggressive clinical course, resistance to treatment, and a rapidly fatal outcome. Eight cases of uterine neoplasms with rhabdoid differentiation have been previously reported. In the three cases where clinical follow-up was available, the patients died of disease within 3 to 17 months after the diagnosis was established. We report two cases of uterine malignant mixed Müllerian tumor (carcinosarcoma) with rhabdoid differentiation. The findings and clinical outcome confirm the aggressive nature of uterine tumors with rhabdoid differentiation. One of the patients died of disease 3 months after initial operative treatment while the other patient's tumor recurred in 1 month and she died within 10 weeks. The poor prognosis of these neoplasms makes their histopathologic recognition important.