Application of the newly published International System for Reporting Serous Fluid Cytopathology in atypical and suspicious diagnosis: a four-year retrospective analysis.

INTRODUCTION: Serous fluids offer crucial diagnostic insights, but inconsistent analysis hampers reporting quality, especially in indeterminate (ID) categories like atypia of undetermined significance (AUS) and suspicious for malignancy (SFM). The 2020 International System for reporting Serous Fluid Cytopathology (TIS) aims to standardize communication and reduce reporting disparities. This study evaluates TIS's role in AUS and SFM categories within our institution. MATERIAL AND METHODS: A 4-year retrospective search of cytopathology reports from December 2015 to December 2019 for AUS and SFM diagnoses in pleural, ascitic, pericardial fluids, and peritoneal washings was performed and results reclassified using TIS definitions. The risk of malignancy (ROM) was calculated for existing and reclassified diagnoses. RESULTS: Over 4 years, we received 2998 serous fluid specimens. AUS constituted 2.3% (70 cases), while SFM constituted 0.5% (16 cases). Excluding repeats, 80 cases were TIS-reviewed. Sixteen cases of ID diagnoses were reclassified. Two cases of AUS were changed to negative for malignancy (NFM) and 12 to SFM. Two SFM cases were upgraded to malignancy. ROM shifted from 63% to 60% for AUS and 100% to 85% for SF (TIS's ROM range: AUS: 66% ± 10%; SFM: 82% ± 4.8%). CONCLUSIONS: This institution's ID diagnosis rate is low. AUS ROM is challenging but aligns with TIS, primarily favoring benign. All SFM diagnoses are highly suspicious but quantitatively inadequate for definitive malignancy, explaining the elevated ROM. AUS rate should gauge quality, not serve as a catch-all category. Algorithmic cytology with cell blocks and ancillary studies aids reclassification. TIS is user-friendly and is a consistent methodology for standardized reporting. Further studies are needed to evaluate ROM and define reproducible diagnostic criteria for each category for better system utilization.

Under Disguise: A Concealed Case of Acute Hepatitis A Infection.

Acute hepatitis A virus infection is routinely identified through a thorough patient history in conjunction with liver chemistries and viral serologies. The diagnosis has the potential to be delayed when the clinical picture is obscured with another, seemingly more urgent presenting pathology with overlapping features. Here, we describe the case of a young female who presented with acute calculous cholecystitis with concurrent acute hepatitis A virus infection.

Nephrogenic Adenoma Arising From a Female Urethral Diverticulum: A Case Report and Potential Diagnostic Pitfalls.

Nephrogenic adenoma is a benign lesion of the urothelial tract characterized by tubules surrounded by thick, hyalinized basement membranes. There is a great variety of architectural patterns within nephrogenic adenomas, including patterns that mimic malignancy, such as focal clear or hobnail cells, areas of significant nuclear atypia, mitosis, and isolated cystic changes. This represents a diagnostic pitfall, where a malignant lesion can be mistaken for a nephrogenic adenoma, leading to a delay in diagnosis and treatment that adversely affects the outcome. In this case report, we describe a nephrogenic adenoma arising in a female urethral diverticulum and discuss the differential diagnosis, which includes clear cell carcinomas, microcystic variant urothelial carcinomas, and Skene's gland cysts.

A Rare Case of Erosive Esophagitis Due to Sarcina Ventriculi Infection.

Sarcina ventriculi is a Gram-positive anaerobic coccus found in soil that is a rare cause of inflammatory infections of the GI tract. This bacterium has a propensity for causing gastritis in patients with delayed gastric emptying. Of the 66 reported cases in the literature, 10 involved the esophagus. Symptoms of an esophageal infection are non-specific and may be mistaken for long-standing gastroesophageal reflux. We present a case of a 67-year-old female with chronic dysphagia and reflux diagnosed with erosive esophagitis caused by Sarcina ventriculi. Treatment strategies documented in the literature are reviewed.

Primary Hepatic Mesothelial Cyst: A Rare Entity to Be Considered in the Differential Diagnosis of Neonatal Cystic Lesions.

We report two cases of primary hepatic mesothelial cysts in neonates previously identified during perinatal imaging. Both neonatal cases were reimaged in the postnatal period, demonstrating the persistence of these cystic hepatic lesions. In both instances, the decision was made to treat with surgical resection and both patients tolerated the surgery well with no significant postoperative complications. Histopathological examination of these lesions discovered a cuboidal lining that was calretinin and WT1 positive and CD31 negative, indicating the diagnosis of a mesothelial cyst of hepatic origin. These cases bring attention to the broad differential diagnosis of congenital primary hepatic cystic lesions, as well as the diagnostic pathway to confirm a primary hepatic mesothelial cyst.

Cholesterol Granuloma: An Unusual Presentation Within the Mandible of a Pediatric Patient.

Cholesterol granulomas, while a common pathological finding, are rarely reported within the mandible. Herein, we report the case of a pediatric patient who presented with a cholesterol granuloma within a periapical cyst, extending from the inferior aspect of tooth #31 to the mandibular condyle, with no prior history of infection or trauma to the region and underwent successful marsupialization of the lesion.