Risk-reduction surgery in BRCA mutation carriers in a Spanish population: adherence and results

[Borderline ovarian tumours: CNGOF Guidelines for clinical practice - Biopathology of ovarian borderline tumors]

OBJECTIVES

Ovarian borderline tumors (OBT) represent a heterogeneous group of lesions with specific management for each histological subtype. Thus, the correct histological diagnosis is mandatory.

MATERIAL AND METHODS

References were searched by PubMed from January 2000 to January 2018 and original articles in French and English literature were selected.

RESULTS AND CONCLUSIONS

OBT should be classified according to the last WHO classification. Any micro-invasion (foci<5mm) or microcarcinoma (foci<5mm with nuclear atypia and desmoplastic stromal reaction) should be indicated in the pathology report. In case of serous OBT, variants (classical or the micropapillary/cribriform) should be indicated (grade C). The peritoneal implants associated with OBT, should be classified as invasive or noninvasive, according to the extension into the underlying adipous tissue. If no adipous tissue is seen the term undetermined should be used (grade B). In case of mucinous OBT bilateral and/or with peritoneal implants or peritoneal pseudomyxoma a search for primitive gastrointestinal, appendiceal or biliopancreatic tumor should be performed (grade C). In case of OBT, a thorough sampling of the tumor is recommended, with 1 block/cm and 2 blocks/cm in case of mucinous OBT, serous OBT micropapillary variant, OBT with intraepithelial carcinoma or/and micro-invasion. Peritoneal implants should be examined in toto. Omentum without macroscopic lesion should be sampled in 4 to 6 blocks (grade C). In case of ovarian cyst suspicious for OBT, fine needle aspiration is not recommended (grade C). In case of ovarian tumor suspicious for OBT, intraoperative examination should be performed by a gynecological pathologist (grade C).

Through the glass darkly: intraepithelial neoplasia, top-down differentiation, and the road to ovarian cancer

It is currently hoped that deaths from extra-uterine high-grade serous cancer (HGSC) will be reduced via opportunistic salpingectomy in healthy women. Accumulated data implicate the fimbria as a site of origin and descriptive molecular pathology and experimental evidence strongly support a serous carcinogenic sequence in the Fallopian tube. Both direct and indirect ('surrogate') precursors suggest that the benign tube undergoes important biological changes after menopause, acquiring abnormalities in gene expression that are often shared with malignancy, including PAX2, ALDH1, LEF1, RCN1, RUNX2, beta-catenin, EZH2, and others. However, the tube can be linked to only some HGSCs, recharging arguments that nearby peritoneum/ovarian surface epithelium (POSE) also hosts progenitors to this malignancy. A major sticking point is the difference in immunophenotype between POSE and Müllerian epithelium, essentially requiring mesothelial to Müllerian differentiation prior to or during malignant transformation to HGSC. However, emerging evidence implicates an embryonic or progenitor phenotype in the adult female genital tract with the capacity to differentiate, normally or during neoplastic transformation. Recently, a putative cell of origin for cervical cancer has been identified in the squamo-columnar (SC) junction, projecting a model whereby Krt7+ embryonic progenitors give rise to immunophenotypically distinct progeny under stromal influences via 'top down' differentiation. Similar differentiation can be seen in the endometrium with a parallel in juxtaposed mesothelial and Müllerian differentiation in the ovary. Abrupt mesothelial-Müllerian transitions remain to be proven, but would explain the rapid evolution, short asymptomatic interval, and absence of a defined epithelial starting point in many HGSCs. Resolving this question will require accurately distinguishing progenitor from progeny tumour cells in HGSC and pinpointing where initial transformation and trans-differentiation occur, whether in the tube or POSE. Both will be critical to expectations from prophylactic salpingectomy and future approaches to pelvic serous cancer prevention.