Spindle cell ossifying amyloidotic tumor of the fallopian tube

We report a unique tumor of the fallopian tube that was an incidental finding in a 60-year-old woman. The tumor was characterized by nests of spindle cells embedded in a partially ossified, hyalinized stroma, that also contained amyloid and basement membrane-like material. The histologic appearance of the tumor cells suggested an epithelial nature, but no immunohistochemical or ultrastructural evidence of such was found. The circumscription of the tumor and its lack of mitotic activity and cytologic atypia suggest a benign nature, but the histogenesis and appropriate classification of the tumor remain unclear.