Fig. 8.
Biphenotypic sinonasal sarcoma. A The right-sided tumor involves the nasal cavity with bone erosion. B The tumor is infiltrative and often entraps downward invaginations of surface respiratory-type epithelium. C The tumor grows as fascicles of uniform spindle cells with minimal mitotic activity or atypia. Slit-like vessels are common. D In some cases the tumor can show overt rhabdomyoblastic differentiation in the form of strap cells