title: PNET/Ewing's sarcoma of the rectum: a case report and review of the literature.
abstract: A 34-year-old female presented with anorectal pain and rectal bleeding due to an extensive rectal tumour. A trephine loop ileostomy was fashioned and biopsies were initially reported to show a poorly differentiated cloacogenic carcinoma. CT revealed numerous liver metastases. A histological review and immunohistochemical studies subsequently favoured a primitive neuroectodermal tumour (PNET). Stem-cell supported chemoradiotherapy resulted in complete resolution of her primary tumour and liver metastases. Serial CT scanning and endoscopy revealed no recurrence after 7 years of follow-up, when she presented with a malignant anal fissure. Imaging and subsequently abdominoperineal resection revealed no evidence of metastases from either the anal cancer or the PNET tumour. Histopathology showed a T1N0R0 basaloid squamous carcinoma originating from grade III squamous intraepithelial neoplasia with no obvious wart viral infection.
authors.affiliation: West Wales General Hospital, Carmarthen, Carmarthenshire SA31 2AF, UK.
authors.forename: Omar M
authors.initials: OM
authors.lastname: Aboumarzouk
authors.forename: Robert
authors.initials: R
authors.lastname: Coleman
authors.forename: John R
authors.initials: JR
authors.lastname: Goepel
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Shorthouse