Fallopian tube metastases of non‐gynaecological origin: a series of 20 cases emphasizing patterns of involvement including intra‐epithelial spread

Abstract

To determine the frequency and distribution of Fallopian tube involvement in patients with ovarian metastases of non-gynaecological origin. All Fallopian tube tissue was processed for histological examination in a consecutive series of 31 patients with ovarian metastases of non-gynaecological origin. The most common primary sites were appendix (n = 10) colon (n = 7), stomach (n = 6) and breast (n = 4). Twenty cases (65%) showed at least one type of tubal spread. Mural involvement was most common (14 cases) but serosal, intra-vascular, intra-epithelial and intra-lumenal spread were also identified in 12, 9, 8 and 11 cases respectively. Intra-epithelial involvement was restricted to the fimbrial epithelium and mimicked tubal carcinoma in situ (CIS) architecturally. Pagetoid invasion was noted in two of the cases. The Fallopian tubes are commonly involved in patients who have neoplasms metastatic to the ovaries. Metastases may show a CIS-like pattern of intra-epithelial spread and therefore small serous CIS-type lesions may not represent proof of tubal tumour origin in patients who have high-stage pelvic serous carcinomas. The frequency of intra-lumenal tumour cells supports transtubal spread as a likely mechanism for mucosal involvement by metastatic tumours involving the lower genital tract.