Ascitic positive cytology and intraperitoneal metastasis in ovarian dysgerminoma

Metastatic Carcinoma in Effusions

Serous cavity may be involved by any neoplasm, including very rare examples of involvement by central nervous system tumors leading to a malignant effusion. The serous cavity lining is rich in lymphatics with lymphatic lacunae opening directly through narrow gaps (stoma) in the lining. Carcinomas mainly metastasize to serosa via the lymphatic vessels, which may be blocked leading to effusion. Primary carcinomas of organs such as lung, intestines, liver, ovary, etc., lined by serosal membranes may spread by direct extension, resulting in malignant effusions. As standard of practice, unless specified, cytopathologic examination of serous effusions implies detection of malignant cells.

As compared to a surgical biopsy from a small focal area of an extensive serosal surface, effusion fluid from respective cavity exfoliates the cells from the entire serosal surface with minimal chance of sampling artifact. Because of this, effusion fluid cytology generally provides a higher diagnostic yield as compared to biopsy of the serous lining, as demonstrated by some studies. However, various challenges related to effusion fluid cytology makes the interpretation of effusion fluid cytology a field with potential misinterpretations, especially for those without proper experience or training.

Developing and following a methodical approach is important for appropriate cytologic examination of effusion fluids. Proper approach may achieve definitive interpretation even without ancillary tests. However, lack of appropriate approach and processing may introduce a significant variation in interpretation due to combination of well-recognized diagnostic pitfalls, which may lead to lower reproducibility and even serious misinterpretations.

Current review discusses in brief appropriate approach to processing and evaluating effusion fluid cytology for metastatic carcinoma. At general level, this is comparable to that of other specimens; however, it is critical to modify with reference to the limitations associated with effusion cytology.

Malignant ascites occurs most often in patients with high-grade serous papillary ovarian cancer at initial diagnosis: a retrospective analysis of 191 women treated at Bayreuth Hospital, 2006-2015

BACKGROUND

Malignant ascites often develops in patients with ovarian cancer, but there is a lack of more detailed characterization of the different histological subtypes.

METHODS

Ascites specimens from patients with ovarian cancer who were treated at Bayreuth Hospital from 2006 to 2015, with follow-up until December 2016, were reevaluated retrospectively.

RESULTS

A total of 191 women (mean age 64 years, range 48-79) were included, of whom 180 (94.2%) had carcinoma, three (1.6%) had malignant mixed müllerian tumors (MMMTs), four (2.1%) had sex cord-stromal tumors (SCSTs), three (1.6%) had germ cell tumors (GCTs), and one (0.5%) had a sarcoma. The carcinoma group comprised 134 (70.1%) patients with high-grade serous papillary ovarian cancer, 17 (8.9%) with low-grade serous papillary ovarian cancer, 10 (5.3%) with mucinous carcinomas, nine (4.7%) with endometrioid carcinomas, six (3.1%) with clear cell carcinomas, and four (2.1%) with neuroendocrine tumors. The latter group consisted of two patients with mixed neuroendocrine-nonneuroendocrine tumors (MiNENs), one with only a small cell carcinoma (SCCO), and one with a mucinous carcinoid. The noncarcinomatous group of eight patients (4.2%) included three (1.6%) with Sertoli-Leydig cell tumor and mature cystic teratoma (MCT), one (0.5%) with a granulosa cell tumor, and one with a leiomyosarcoma. A statistically significant difference in the proportion of patients with malignant ascites was observed, at 17.7% (3/17) in those with low-grade serous papillary ovarian cancer and 91.8% (123/134) in those with high-grade serous papillary ovarian carcinomas. In both patients with MiNEN, the glandular tumor cell component was found in the ascites. Tumor cells were found in the ascitic fluid in 50% (5/10) of patients with mucinous ovarian carcinomas, 16.7% (1/6) of those with clear cell carcinomas, and 33.3% (1/3) of those with MMMTs. The two patients (2/3; 66.7%) with neoplastic squamous cell components in MCT and the only patient with a granulosa cell tumor in the SCST group (1/4; 25%) had malignant cell populations in the ascites, whereas patients with endometrioid cell carcinoma and leiomyosarcoma lacked tumor cells in the ascites. The malignant ascites was detected at the initial diagnosis in all 138 (100%) patients with ovarian neoplasms.

CONCLUSIONS

High-grade serous papillary ovarian cancer was the main histological subtype most frequently found in ascites fluid in this series. The significant difference (P < 0.00001) in the malignancy rate in comparison with low-grade serous papillary carcinoma confirms the histological distinction between the two entities. Initial evidence of ovarian cancer in ascites fluid allows correct primary diagnosis in cytology specimens and is important for staging and prognosis.