The role of cytology in endometrial cancer: Diagnostic and clinical considerations from peritoneal/pelvic washings. Is it still a heated debate?

Abstract

The diagnostic and clinical interpretation of peritoneal/pelvic washing (PW) cytology in endometrial carcinoma (EC) remain controversial. 1-5 The incidence of malignant cytological diagnoses varies widely in different studies ranging from 4.9% to 40%, mostly due to the use of different diagnostic criteria and different thresholds for making a specific diagnosis. 1-5 Moreover, the clinicopathological significance of positive results, especially in women affected by early stage EC, remains an open debate. 1-5 While the role of cytology has been clearly defined for ovarian cancer, its prognostic significance for EC and its exact role in guiding treatment decision making are problematic. 1-5 In this issue of Cancer Cytopathology, Davis et al 6 discuss their diagnostic experience and technical considerations for the use of peritoneal/pelvic cytology in EC patients, raising the unsolved question of both prognostic and staging roles of cytology in EC, particularly in the absence of other evidence of extrauterine spread. 1,2,6 EC is the most common gynecologic cancer in developed countries and, to date, represents a heterogeneous group of diseases with different morphological and molecular features. 7 According to the Cancer Genome Atlas model, 4 molecular categories of EC are recognized: 1) ultramutated (DNA polymerase epsilon mutated), 2) hypermutated secondary to microsatellite instability, 3) low copy number, and 4) high copy number (serous-like). 8 Despite recent advances in defining EC, more than 20% of women with EC still experience recurrences and metastases and eventually die of disease. 9,10 Together with the known biopathological parameters (lymph node status, histological type and grade, stage of disease, depth of myometrial invasion, lymphovascular space involvement, cervical involvement, microcystic elongated and fragmented-MELF pattern of myometrial invasion), the adoption of molecular diagnostic categories in routine clinical practice and the evaluation of WT1 and L1CAM immunohistochemical expression have recently emerged as promising prognostic factors in EC patients. 1,10-13 According to many experts, malignant cytology is associated with adverse outcome only when accompanied by extrauterine spread of the disease. 3,4 However, a positive cytological diagnosis may be considered an indicator of aggressive tumor behavior being related to other adverse prognostic factors, such as high-grade disease, nonendometrioid histology, deep myometrial invasion, lymphovascular space invasion, and lymph node metastases. 1-5 In the study by Davis et al, cytological specimens (both ThinPrep and cell block preparations) from PW of EC patients were retrospectively reviewed and analyzed according to the new diagnostic criteria proposed

Diagnostic impact of safety protocols for processing peritoneal washing specimens during the global pandemic of coronavirus disease 2019: A comparative study from 195 cytological samples

“…1,2 The prognostic significance of PW cytology is well documented in gynaecological, gastric, pancreatic, and oesophageal tumours. [3][4][5][6][7] Recently, the worldwide cytopathologists' community introduced a 5-tier International System for Reporting Serous Fluid Cytology (TIS) using specific diagnostic categories based on welldefined criteria and risk of malignancy (ROM): unsatisfactory (ND), benign (NFM), atypia of uncertain significance (AUS), suspicious for malignancy (SFM), and malignant (MAL). 8 In this regard, a recent paper on the cytology of serous fluids demonstrated the good diagnostic performance of the TIS system in terms of specificity and predictive value, confirming its useful role in the cytological diagnosis of effusions.…”

“…The prognostic significance of PW cytology is well documented in gynaecological, gastric, pancreatic, and oesophageal tumours 3‐7 …”