Epithelioid hemangioendothelioma of soft tissue: report of a case with ultrastructural observations.

The ultrastructure of an epithelioid hemangioendothelioma arising in the soft tissues of the neck of an 18-year-old female is reported. Comparison with similar tumors in other sites from the authors' electron microscopy files indicates that diffuse nonspecific intermediate filaments, pinocytotic vesicles, intracytoplasmic lumens, and pericytic cells are frequent but variable features of this neoplasm.