Morphologic and Immunocytochemical Features of High-Grade Serous Carcinoma of Ovary in Ascitic Fluid Effusion and Fine-Needle Aspiration Cytology

Abstract

Objectives High-grade serous carcinoma (HGSC) is the most common ovarian malignancy. The role of cytopathology in obtaining tissue diagnosis before institution of neoadjuvant chemotherapy (NACT) was evaluated. Methods All histopathology-proven HGSC specimens between 2015 and 2018 with prior cytopathologic diagnosis by ascitic fluid evaluation or fine-needle aspiration (FNA) of ovarian mass were reviewed with cell block immunocytochemistry for CK7, CK20, PAX8, WT1, and p53. Results Of 288 cases of HGSC, pre-NACT cytology diagnosis was established in 32% (93/288), with specific HGSC diagnoses made on ascitic fluid in 88% (82/93) and by ovarian mass FNA in 12% (11/93). The ascitic fluid showed moderate/high cellularity with papillary clusters in 76% (71/93) cases. Cell block immunocytochemistry showed tumor cells positive for CK7, PAX8, and WT1. p53 showed mutant or null-type positivity in 65% (33/51) and 33% (17/51) of cases, respectively, with 100% concordance with subsequent histopathology specimens. Poor/intermediate response to chemotherapy was shown in 75% of cases. Conclusions Combined assessment of cytomorphology, cell block histomorphology, and ancillary immunohistochemical testing, including PAX8, WT1, and p53, allows for specific pre-NACT diagnoses of HGSC in ascitic fluid and ovarian FNA cytology. This practice allows for initiation of chemotherapy and diminution of disease burden prior to definitive surgical therapy.

Characteristics of Pelvic Cytology in Patients with Gynecologic Malignancies: Comparison of Pre and Post-Neoadjuvant Specimens

“…This would be a fruitful area for future study in an expanded population. Similar to prior studies, the malignant cells were present most commonly in clusters [15]. Such clusters can show morphologic overlap with other entities in the differential diagnosis, including malignant mesothelioma [16] and carcinomas of other pelvic organs [17].…”

“…Though the practice at our institution is targeted toward oncologic care of women, these specimens proved elusive. This has not proven the case in other studies [15], and perhaps reveals a variation in practice pattern of the oncologists at this facility. A larger, collaborative cohort between institutions might facilitate expansion of the cohort.…”

“…While the staging protocol for some gynecologic malignancies had removed PC from staging criteria [14], it is possible that in the setting of neoadjuvant treatment, this could change. Increasingly, pretreatment samples are being utilized to diagnose gynecologic malignancies, especially in HGSC of the ovary, often on PC alone [15]. It is possible that the serious clinical treatment of NAC can be started based on the diagnosis on pelvic washings alone, provided a specific enough diagnosis is rendered, for example, a diagnosis of HGSC [7].…”

Educational Case: High-Grade Serous Carcinoma of the Ovary

“… 9 If the primary malignancy is unknown during peritoneal fluid cytology evaluation, immunohistochemical profiles often help determine the site of origin of gynecologic tract. 10 Involvement of peritoneal fluid confers a higher stage than disease confined to the adnexa. Hence, peritoneal lavage fluid/ascitic fluid is routinely sent for cytologic evaluation while performing surgical cytoreduction and staging.…”

Diagnostic challenges in the gray-zone lesions of fine-needle aspiration cytology

“…A minimal panel comprising CK7, PAX8, WT1, and p53 can be used to diagnose HGSC. [ 20 ] A basic panel to differentiate primary ovarian and metastatic adenocarcinoma should include PAX8 (Mullerian marker), CK7, CK20, WT1, and p16. CK7 negative (–)/CK20 positive (+), CDX2+ indicates a colorectal primary while a CK7+, CK20–, PAX8+, indicates an ovarian primary.…”