Comparison of the recommendation of international autoimmune hepatitis pathology group 2022 and the simplified criteria for autoimmune hepatitis 2008: A preliminary study.

Background and Aim: The histological diagnosis of autoimmune hepatitis (AIH) is challenging. A new consensus recommendation was provided by the International AIH Pathology Group to address the problems in the histological diagnosis. The purpose of this study is to compare the 2008 'simplified' criteria for AIH with the 'consensus recommendation' of 2022 in terms of diagnostic sensitivity. Materials and Methods: A retrospective analysis was conducted on pathological specimens of patients diagnosed with Autoimmune Hepatitis (AIH) between 2010 and 2022. Out of 188 patients enlisted, 88 were selected based on exclusion criteria. The specimens were examined by two experienced hepatopathologists and a resident pathologist. All specimens were analyzed using both the "simplified" criteria and the new consensus recommendations. Results: Out of a total of 78 patients, the 2022 consensus recommendations raised the diagnostic category of 16 patients (20.5%) to a higher level. Six patients who were previously diagnosed as "atypical" were now considered "possible AIH", while 10 patients with a "compatible" diagnosis were elevated to "likely AIH" category. No patients were found to fall into a lower diagnostic category according to the new recommendations. A significant difference in diagnostic sensitivity was observed between the 2008 criteria and the 2022 consensus report (p<0.001). Conclusion: The 2022 consensus recommendation may be more sensitive in the diagnosis of AIH in comparison to the 2008 'simplified' histological criteria. More studies are needed both for the validation of the sensitivity of the new consensus recommendation and for the determination of the specificity.

Benign Multicystic Peritoneal Mesothelioma: Two Rare Cases and Review of the Literature.

BACKGROUND: Benign multicystic peritoneal mesothelioma is a multiloculated cystic mass which originates from the peritoneum. This rare tumor is usually seen in women of childbearing age and has a high recurrence rate after surgery. CASE PRESENTATION: We present two benign multicystic peritoneal mesothelioma cases with different imaging modalities, which were also pathologically proven. CONCLUSION: The imaging features which may be diagnostic should be well known as there are very few reports regarding this entity.

Risk of Malignancy Using the Diagnostic Categories Proposed by the World Health Organization International System for Reporting Pancreaticobiliary Cytopathology.

BACKGROUND: The World Health Organization (WHO) proposed an updated reporting system for pancreaticobiliary cytology, which moves low-grade malignancies to "positive for malignancy" group and serous cystadenoma to "negative for malignancy" group. The WHO system also created two new categories, namely, pancreatic neoplasia-low grade (PaN-Low) and pancreatic neoplasia-high grade (PaN-High), which includes neoplastic mucinous cysts and stratifies them according to their cytologic atypia. The risk of malignancy (ROM) of the new categories of the WHO system needs to be defined. METHODS: Cytologic slides of all patients, who underwent endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) biopsy at our institution from January 2010 to December 2021 and had a histopathological or clinical follow-up of at least 6 months, were reviewed and reclassified under the Papanicolaou Society of Cytopathology (PSC) and WHO reporting systems. The absolute ROM was calculated for each category of both reporting systems. RESULTS: A total of 420 EUS-FNA samples from 410 patients were reviewed and reclassified. The absolute ROM for the proposed WHO system was 35% for "nondiagnostic," 1.0% for "negative for malignancy," 69.0% for "atypical," 11% for "PaN-Low," 100% for "PaN-High," 91% for "suspicious for malignancy," and 100% for "malignant." Comparatively, the absolute ROM under the PSC reporting system was 34% for "nondiagnostic," 1.0% for negative (for malignancy), 50.0% for "atypical," 0.0% for "neoplastic: benign," 16% for "neoplastic: other," 88% for "suspicious for malignancy," and 100% for "positive or malignant." CONCLUSION: The proposed WHO international reporting system has advantages regarding risk stratification improvement and case management.

Pancreatic metastasis of invasive ductal breast carcinoma: A potential diagnostic pitfall.

The 42-year-old patient, diagnosed with Stage IIA breast cancer, completed the postoperative adjuvant chemotherapy and radiotherapy. At the 11th year of diagnosis, a 3 cm tumor was detected in the pancreas and pancreatectomy was performed. Although the diagnosis of primary pancreatic adenocarcinoma was made at first, then the pancreatic metastasis of breast cancer was discovered. Pancreatic metastasis of breast cancer is extremely rare, and a limited number of patients have been reported in the literature. Here, we report an additional case of this rare tumor and the problems correlating with its diagnosis.