High-grade Pelvic Serous Carcinoma Within the Fallopian Tube Lumen: Real or Artifact?

Tumor cells are occasionally observed in the lumen in histologic sections of the fallopian tube from women with gynecologic cancer. There is some evidence that this finding may be important in endometrial cancer, but its significance is unknown in women with extrauterine pelvic serous carcinomas (tubo-ovarian high-grade serous carcinoma). Fallopian tube sections from 213 women with extrauterine pelvic serous carcinoma were reviewed, and luminal tumor cells were correlated with clinical and pathologic features. Intraluminal tumor cells were found in 84 patients (39%). The presence or absence of luminal tumor cells correlated significantly with serous tubal intraepithelial carcinoma (52% and 33%, respectively, P=0.004), tubal lymphatic invasion (32% and 12%, respectively, P=0.0002), and number of tube sections reviewed (6.6 and 4.9 for lumen-positive and lumen-negative cases, respectively, P=0.0056). There was no correlation with the presence of ascites, peritoneal cytopathologic findings, lymph node metastases, or FIGO stage. In the setting of pelvic serous carcinoma, a substantial portion of fallopian tube tissue is often distorted, fibrotic, and difficult to identify. Since the identification of luminal tumor cells, serous tubal intraepithelial carcinoma and tubal lymphatic invasion all depend on identification of fallopian tube tissue, these correlates with luminal tumor cells could be a result of a higher likelihood of their observation when tubal tissue can be more readily identified and may not necessarily reflect a biologically important phenomenon. It remains unclear whether and in what proportion this finding reflects an artifact of specimen handling.