Vaginal superficial myofibroblastoma: a rare mesenchymal tumor of the lower female genital tract and a study of its association with viral infection.

Superficial myofibroblastoma is a rare mesenchymal tumor in the lower female genital tract. The exact etiology of superficial myofibroblastoma remains unclear. The association of viral infection and mesenchymal tumors has been well established in some particular types of soft tissue tumors. In the lower female genital tract, the intimate correlation of viral infection and tumor pathogenesis has been also proposed. We present a 59-year-old woman with postcoital bleeding for 1 month. The pelvic examination revealed a 2-cm polypoid mass mimicking leiomyoma at the vaginal fornix. Local excision was performed, and the pathological examination revealed a superficial myofibroblastoma. No tumor recurrence was noted during the 12-month follow-up. Pathological differential diagnosis of this tumor from other mesenchymal tumors is essential because of its distinct clinicopathological features. Furthermore, fluorescence in situ hybridization of human papilloma virus (HPV) and Epstein-Barr virus (EBV), as well as immunohistochemical staining of human herpesvirus 8 (HHV8), was negative in tumor cells. To the best of our knowledge, we are the first group to study the possible relationship of viral infection and the occurrence of this mesenchymal tumor. Our results suggested no association of vaginal superficial myofibroblastoma and infection with HPV, EBV, or HHV8.