title: Fallopian metaplastic papillary tumour: an atypical transdifferentiation of the tubal epithelium?
abstract: A metaplastic papillary tumor of the Fallopian tube is an extremely uncommon condition, with odd and confusing features that make it difficult to categorize as benign or borderline. Here, we summarize all the published cases to date and document the case of a 41-year-old woman diagnosed with this alteration after her last childbirth and ensuing tubal ligation. One of the tubes was bulky and filled with a caramel-like substance encircling a blurry spot. Light microscopy detailed a slender stalk covered by eosinophilic, columnar plump cells, showing atypical nuclei and focal budding. Mitotic figures were absent. The immunohistochemistry panel was positive for pan-cytokeratin, epithelial membrane antigen, cyclin D1, and hormone receptors. Additionally, a proliferation index of less than 5% was rated using Ki-67. The true nature of this tumor (reactive vs neoplastic) is uncertain. Nonetheless, its association with pregnancy suggests an adaptive change, likely similar to the atypical transdifferentiation proposed for Arias-Stella reaction.
authors: Anatomical Pathology Division, "Dr. Manuel Gea González" General Hospital, Mexico City, Mexico ; Pathology Unit, Mexico General Hospital, Mexico City, Mexico.
authors: Miguel Fdo
authors: MF
authors: Salazar
authors: Anatomical Pathology Division, "Dr. Manuel Gea González" General Hospital, Mexico City, Mexico.
authors: Isaías Estrada
authors: IE
authors: Moscoso
authors: Anatomical Pathology Division, "Dr. Manuel Gea González" General Hospital, Mexico City, Mexico.
authors: Lorena Troncoso
authors: LT
authors: Vázquez
authors: Pathology Unit, Mexico General Hospital, Mexico City, Mexico.
authors: Nubia Leticia
authors: NL
authors: López García
authors: Pathology Unit, Mexico General Hospital, Mexico City, Mexico.
authors: Paola Andrea
authors: PA
authors: Escalante Abril
keywords: Arias-Stella reaction; Cell transdifferentiation; Fallopian tubes; Metaplastic papillary tumour