Isolated sigmoid colon metastasis from a primary fallopian tube carcinoma: a case report

Isolated metastasis of primary fallopian tube carcinoma (PFTC) is extremely rare. We describe a case of a 41-year-old asymptomatic woman who was referred three years after the initial treatment for PFTC due to elevated sertum CA-125 levels. The abdominal and pelvic CT scans revealed a pelvic mass near the top of the vaginal vault. On surgery, a sigmoid colon tumour was found and a sigmoidectomy was performed. On histopathology the tumour involved the bowel wall from serosa to submucosa, without involvement of the underlying mucosa. Immunohistochemical staining was positive for cytokeratin 7 and negative for cytokeratin 20, and the tumour was determined to be a metastatic müllerian neoplasm, consistent with the initial PFTC. Although this is the first reported case of colon metastasis of PFTC, the possibility of such an unusual site of metastasis should be kept in mind, as PFTC may recur as isolated bowel lesions even in the absence of peritoneal disease.