Restriction of SARS-CoV-2 replication in the human placenta.

Although SARS-CoV-2 can infect human placental tissue, vertical transmission is rare. Therefore, the placenta may function as a barrier to inhibit viral transmission to the foetus, though the mechanisms remain unclear. In this study, we confirmed the presence of the SARS-CoV-2 genome in human placental tissue by in situ hybridization with antisense probes targeting the spike protein; tissue staining was much lower when using sense probes for the spike protein. To the best of our knowledge, this is the first evidence directly indicating inefficient viral replication in the SARS-CoV-2-infected placenta. Additional studies are required to reveal the detailed mechanisms.

Is cell block technique useful to predict histological type in patients with ovarian mass and/or body cavity fluids?

The cell block (CB) technique is a generalized method utilized for the diagnostic evaluation of body cavity fluids. Ascites cytology is one of the most important diagnostic processes for epithelial ovarian cancer. However, in clinical practice, the usefulness of the CB method to diagnose this tumor remains unelucidated. Between 2008 and 2017, 15 peritoneal or pleural fluid samples obtained from patients with ovarian or peritoneal carcinoma or other gastrointestinal malignancies were preoperatively subjected to a diagnostic evaluation to predict the histological type and original organ. The CBs were made from 10% formalin neutral buffer solution fixed sediments of fluid samples after cytological smears were made by conventional method. Four-µm thickness sections were prepared from the cell blocks and stained with immunohistochemical method, using 16 kinds of antibodies and hematoxylin eosin staining method. The cellularity, architectural patterns, and morphological details were also studied. The median (range) age of patients was 73 (35-87) years. The clinical features were identified as follows: pleural effusion in 4, ovarian mass in 7, peritoneal dissemination in 12, para-aortic nodal swelling in one, and liver tumor in one (some overlapping). Five patients had a history of prior malignancy. Finally, we could accurately diagnose the histological type in 9 patients based on subsequent biopsy, surgery, and autopsy. In all 9 women, the clinical diagnosis, CB diagnosis and final pathological diagnosis were consistent. The CB technique may be a helpful modality for evaluating fluid cytology to obtain a final histopathologic diagnosis.

Clinical characteristics of primary peritoneal carcinoma patients: a single-institution experience involving 8 patients.

Primary peritoneal carcinoma (PPC) is treated similarly to advanced epithelial ovarian carcinoma (aEOC); however, the standard approach for the management of PPC is controversial. The objective of this study was to evaluate the clinical features and prognosis of those patients. A retrospective analysis was performed of eight patients with PPC between January 2008 and December 2015. Clinicopathologic parameters, the diagnostic modality, treatment, and oncologic outcome were analyzed. The median age at the time of diagnosis was 72.5 years (range: 55-79), with a median follow-up of 26.5 months (range, 5-74). Most of the PPC developed with carcinomatosis peritonei involving ascites, while some cases developed sporadically in the peritoneal or extraperitoneal cavity without ascites. The most common initial symptom was abdominal fullness, and other symptoms were inguinal tumor, paralysis of the extremities, and respiratory disorder. The preoperative CA125 value was elevated in all patients. In four patients who did not undergo primary surgery, the final diagnoses were determined by the ascites cytology and radiological image. Initial or interval debulking surgery was performed in only two patients. All patients were treated with paclitaxel or docetaxel plus carboplatin. Five showed a complete response (CR), and one showed a partial response (PR). Among the five patients with CR, the median progression-free and overall survival periods were 15 (12-26) and 41.5 (32-74) months, respectively. Three patients without carcinomatosis peritonei showed a relatively favorable prognosis. The management of PPC is generally consistent with that of aEOC; however, in atypical cases, the treatment method should be considered individually.