B-cell prolymphocytic leukemia: an enduring bona fide entity.

B-cell prolymphocytic leukemia (B-PLL) was recognized as a distinct entity in the fourth edition of the World Health Organization (WHO) classification for hematolymphoid neoplasms (WHO-HAEM4); however, its de novo presentation has been removed from the upcoming 5th edition classification (WHO-HAEM5). We present a case of a 65-year-old man with leukocytosis, fatigue, and no organomegaly by imaging. Bone marrow examination showed a prolymphocytoid population comprising 78% of the marrow elements. After thorough exclusion of other entities by clinical parameters and ancillary methods, we concluded that this case represents a de novo case of B-PLL.

5-Hydroxymethylcytosine (5-hmC) loss is a marker of malignancy in biliary neoplasms.

OBJECTIVES: Adenocarcinomas of the biliary tract frequently present diagnostic challenges because of their histologic overlap with benign and preinvasive lesions. The molecular profiles of biliary adenocarcinomas vary by anatomical location. Variations in IDH1/2, common in intrahepatic cholangiocarcinoma, can lead to defective production of 5-hydroxymethylcytosine (5-hmC). Limited ancillary studies are available for biliary adenocarcinomas, and loss of 5-hmC staining could serve as a helpful ancillary diagnostic tool for biliary tract malignancies. METHODS: We evaluated 93 cases-20 benign biliary lesions, 15 preinvasive biliary neoplasms, 46 invasive biliary carcinomas, and 12 pancreatic adenocarcinomas-for 5-hmC staining. Preoperative biopsies from 16 cases of biliary carcinoma were also stained. Sixteen nonneoplastic/reactive bile duct biopsies served as controls. RESULTS: Loss of 5-hmC was seen in 41 of 46 (89.1%) biliary malignancies vs 0 of 20 benign tumors (P < .001), for a sensitivity and specificity of 89.1% and 100%, respectively. Intrahepatic cholangiocarcinoma showed loss of 5-hmC in 11 of 13 (84.6%) cases, similar to the 30 of 33 (90.9%) cases in other biliary adenocarcinomas (P = .61). Similarly, 5-hmC loss was more frequent in distal bile duct adenocarcinomas than in pancreatic ductal adenocarcinomas, at 15 of 17 (88.2%) vs 4 of 12 (33.3%), respectively (P = .0045). There was no difference in the frequency of 5-hmC loss in patients that received neoadjuvant therapy vs those who did not (90.9% vs 88.6%, P > .99). 5-hmC immunohistochemistry in preoperative biopsies was concordant with the resection specimen in 81.3% (13/16) of cases. CONCLUSIONS: Loss of 5-hmC is not unique to intrahepatic cholangiocarcinoma among biliary carcinomas, but is a useful diagnostic marker differentiating malignancies of the biliary tree from benign mimics.

Risk of malignancy associated with the diagnostic categories proposed by the Papanicolaou Society of Cytopathology for pancreaticobiliary specimens: An institutional experience.

BACKGROUND: The guidelines published by the Papanicolaou Society of Cytopathology (PSC) intend to unify the reporting language in pancreaticobiliary specimens and improve communication between cytopathologists and clinicians. The six categories in the system will determine the best management for patients. However, there is limited evidence regarding the risk of malignancy (ROM) associated with each category. METHODS: A retrospective search was performed for pancreaticobiliary fine-needle aspiration (FNA) reports with corresponding surgical follow-up. Cases were reclassified according to the PSC. The ROM, sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each category. RESULTS: A total of 297 cases were identified and reclassified as: 30 nondiagnostic (category I), 45 negative for malignancy (II), 20 atypical (III), 42 neoplastic: other (IVB), 19 suspicious for malignancy (V), and 141 malignant (VI). The absolute ROM was 10% for category I, 8.9% for category II, 60% for category III, 4.8% for category IV when the neoplasms were not characterized as malignant, and 100% when categorized as malignant; 100% for category V, and 95.7% for category VI. Sensitivity, specificity, positive predictive value, and negative predictive value for neoplasia and malignancy, including categories IV to VI, were 96.6%, 88.4%, 97.5%, and 84.4%, respectively. CONCLUSIONS: The categories developed by the PSC stratify the ROM. Aspirates designated as categories V and VI had the highest ROM. Our rate of atypical category complies with the recommended rate of <10%. This scheme provides valuable information to clinicians treating patients with pancreatic lesions.

Leukemic Infiltration of Myocardium Presenting as Cardiac Arrest.

Clinically significant myocardial infiltration by leukemic cells is a rare phenomenon. We describe a case of a 47-year-old woman with newly diagnosed acute myeloid leukemia and pleuritic chest pain with rapid cardiopulmonary decompensation. Post-mortem analyses showed fibrinous pericarditis and extensive leukemic infiltration of the myocardium. (Level of Difficulty: Intermediate.).

STAT3 gain-of-function mutation in a patient with pulmonary Mycobacterium abscessus infection.

BACKGROUND: Signal transducer and activator of transcription 3 (STAT3) is a transcription factor involved in cellular proliferation, apoptosis, and differentiation. Mutations in the STAT3 gene have been associated with dysregulation of the immune system giving rise to primary immunodeficiency syndromes (PID). Clinically, patients may present with very broad manifestations, and its diagnosis is usually very challenging. Proper treatment remains unclear, and limited options are available. METHODS: We report an adult male patient with long-standing history of immunodeficiency, who was found to have Mycobacterium abscessus infection. Two-hundred and seven immunogenes were sequenced using next-generation sequencing technology (NGS). RESULTS: A STAT3 heterozygous missense pathologic variant was identified in the patient located in the transactivation domain (TA) of STAT3, associated with a gain of functionality, leading to recurrent bronchopulmonary infections, and involvement of multiple organ systems. CONCLUSIONS: Severe cases of autoimmunity should prompt for evaluation of PIDs in the setting of genetic mutations. Anti-IL-6 therapy may benefit patients with STAT3 GOF mutations. These patients should also be screened for lymphoproliferative disorders.

Percentages of CD4+CD8+ Double-positive T Lymphocytes in the Peripheral Blood of Adults from a Blood Bank in Bogotá, Colombia

Objective: CD4+CD8+ double-positive T-cells (DPTs) have been classified as a separate T-cell subpopulation, with two main phenotypes: CD4high CD8low and CD4low CD8high. In recent years, the relevance of DPTs in the pathogenesis of infections, tumors, and autoimmune diseases has been recognized. Reference values among healthy individuals remain unknown. Therefore, the aim of this study is to provide a reference value for DPTs in peripheral blood from healthy donors in a blood bank in Bogotá, Colombia, and to determine the activation status using a surface marker. Materials and Methods: One hundred healthy donors were enrolled in the study. Peripheral blood cells were stained for CD3, CD4, CD8, and CD154 (CD40L), and cellular viability was assessed with 7-aminoactinomycin D and analyzed by flow cytometry. Results: The median value for DPTs was 2.6% (interquartile range=1.70%-3.67%). Women had higher percentages of DPTs than men (3.3% vs. 2.1%). The subpopulation of CD4low CD8high showed higher expression of CD154 than the other T-cell subpopulations. Conclusion: DPT reference values were obtained from blood bank donors. A sex difference was found, and the CD4low CD8high subpopulation had the highest activation marker expression.