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.

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).

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.

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.

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

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: CD4 CD8 and CD4 CD8. 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.