Parachordoma/myoepithelioma of the kidney: first report of a myxoid mimicry in an unusual location.

We report a case of parachordoma (or myoepithelioma) of the right upper kidney in a 56 year-old male patient. Light microscopic features of the tumor exhibited epithelioid, glomoid, and spindle cells with eosinophilic and vacuolated cytoplasm as well as round to oval nuclei. These cells were embedded in a myxoid and hyaline stroma separated by a fibrous tissue with minimal cellular atypia and a few small nucleoli. Immunohistochemically, the tumor cells were immunoreactive for epithelial membrane antigen, calponin, vimentin, S-100, and type-IV collagen. All kidney and adrenal were resected, and the patient was carefully followed up. During the 11 months follow-up, recurrence and metastases were not observed. To our knowledge, this study is the first to document a case of parachordoma/myoepithelioma of the kidney. We add this new case to existing tumors and discuss its distinction from other types.