American Journal of Clinical Pathology

OBJECTIVES: IDH1 and IDH2 are among the most commonly mutated genes in myeloid neoplasms (MNs). It has been proposed that IDH2 R172 mutations (mR172) define a molecular subtype of acute myeloid leukemia (AML), but the clinicopathologic features of AML with mR172 have not been fully described. METHODS: We retrospectively identified and characterized all mR172 MNs with increased blasts in our archive for comparison to a similar number of MNs with IDH2 R140 (mR140) and IDH1 R132 (mR132) mutations (n = 39)...

OBJECTIVES: The present study used immunohistochemistry (IHC) to detect antigen Ag85B in tissue sections and aimed to evaluate its validity in histopathologic diagnosis of tuberculosis (TB). METHODS: In total, 204 patients with confirmed TB and 40 other diseases were included in the present study. Ziehl-Neelsen (Z-N) stains, IHC (anti-Ag85B), and quantitative fluorescence polymerase chain reaction were used to detect acid-fast bacilli, Mycobacterium tuberculosis (MTB) antigen, and MTB DNA...

OBJECTIVES: To demonstrate the clinical features and prognostic impact of cyclin D1 positivity in patients with amyloid light chain amyloidosis (AL). METHODS: We consecutively included 71 patients diagnosed with AL with cyclin D1 positivity between February 2008 and January 2022. t(11;14) was examined through interphase fluorescence in situ hybridization using bone marrow cells. RESULTS: The median age of the patients was 73 years, and 53...

OBJECTIVES: Clinical experts recommend against testing for lupus anticoagulant (LAC) during anticoagulation. METHODS: We quantitated the risk of a single-positive dilute Russell viper venom time (dRVVT) result or partial thromboplastin time-based phospholipid neutralization (PN) result on anticoagulation. RESULTS: Any anticoagulation led to a fourfold greater likelihood of single-positive results, primarily by rivaroxaban (odds ratio [OR] = 8...

OBJECTIVES: Cytomorphology is known to differ depending on the processing technique, and these differences pose a problem for automated diagnosis using deep learning. We examined the as-yet unclarified relationship between cell detection or classification using artificial intelligence (AI) and the AutoSmear (Sakura Finetek Japan) and liquid-based cytology (LBC) processing techniques. METHODS: The "You Only Look Once" (YOLO), version 5x, algorithm was trained on the AutoSmear and LBC preparations of 4 cell lines: lung cancer (LC), cervical cancer (CC), malignant pleural mesothelioma (MM), and esophageal cancer (EC)...

OBJECTIVES: Amyloid light chain (AL)-κ and AL-λ share common histopathologic changes; however, the potential difference in clinical manifestations, histologic findings, and clinical significance between the 2 subtypes remain unclear. METHODS: In a retrospective study, 94 kidney biopsies for AL amyloidosis were evaluated using the composite scarring injury score (CSIS) and amyloid score (AS). Results were then compared between AL-κ and AL-λ...

OBJECTIVES: To provide an institutional experience with cases diagnosed as carcinoma ex pleomorphic adenoma (CXPA), including the cytologic and histologic findings and clinical follow-up, followed by a comparison to the experience documented in the literature. METHODS: We identified cases of CXPA diagnosed at our institution from 2011 to 2021 and reviewed the cytologic and histologic diagnoses, as well as the treatment and clinical outcomes. Additionally, a literature review of the English literature was performed on CXPAs from 2011 to 2021...

OBJECTIVES: This study compares the effectiveness of an interactive e-learning module with a traditional text-based method for teaching peripheral blood smear analysis. METHODS: Pathology trainees at Accreditation Council for Graduate Medical Education residency programs were asked to participate. Participants completed a multiple-choice test on peripheral blood smear findings. Trainees were randomized into completing an e-learning module or a PDF reading exercise with the same educational content...

OBJECTIVES: Massive fetomaternal hemorrhage (FMH) is rare and reported to be the cause in approximately 3% of all fetal deaths. Maternal management of massive FMH includes prevention of Rh(D) alloimmunization in Rh(D)-negative mothers by administration of Rh(D) immune globulin (RhIG). METHODS: We describe a case of a 30-year-old O-negative, primigravida woman who presented at 38 weeks of gestation with decreased fetal movements. She underwent an emergency cesarean section and delivered an O-positive baby girl who died shortly after birth...

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OBJECTIVES: Histopathology is an important method for diagnosing extrapulmonary tuberculosis, yet tissue sections are often negative for mycobacteria after use of acid-fast stain (AFS). This study investigated the mechanism of AFS use and the detrimental effect of histologic processing-in particular, xylene deparaffinization-on AFS and mycobacterial detection. METHODS: The target of the fluorescent Auramine O (AuO) AFS was investigated using triple staining with DNA- and RNA-specific dyes...

OBJECTIVES: To determine the prognostic significance of the maximum allowable percentage of Gleason pattern 4 (GP4) at prostate biopsy compared with adverse pathology observed at radical prostatectomy (RP) to expand active surveillance eligibility among a cohort with intermediate risk of prostate cancer. METHODS: A retrospective study of patients with grade group (GG) 1 or 2 prostate cancer on prostate biopsy with subsequent RP was performed at our institution. A Fisher exact test was used to understand the relationship among GP4 subgroups (0%, ≤5%, 6%-10%, and 11%-49%) assigned at biopsy and adverse pathologic findings at RP...

OBJECTIVES: We explored features of the angiosarcoma (AS) tumor microenvironment to discover subtypes that may respond to immunotherapy. METHODS: Thirty-two ASs were included. Tumors were studied by histology, immunohistochemistry (IHC), and gene expression profile using the HTG EdgeSeq Precision Immuno-Oncology Assay. RESULTS: Comparing cutaneous and noncutaneous ASs, the second group showed 155 deregulated genes, and unsupervised hierarchical clustering (UHC) delineated two groups: the first mostly cutaneous AS and the second mainly noncutaneous AS...

OBJECTIVES: Plasma cell-rich rejection (PCCR), also known as "plasma cell hepatitis" or "de novo autoimmune hepatitis," is a cause of allograft dysfunction occurring post-liver transplantation (LT). Patients often develop allograft failure and may require repeat LT. PCRR may fall within the spectrum of different histologies associated with antibody-mediated rejection (AMR), which is associated with donor-specific antibodies (DSAs) and positive complement component C4 (C4d) immunostaining...

OBJECTIVES: T-cell prolymphocytic leukemia (T-PLL) is a rare mature T-cell leukemia usually characterized by inv(14)(q11.2q32)/t(14;14)(q11.2;q32). In this study, we aimed to investigate the clinicopathologic features and molecular profile of T-PLL associated with t(X;14)(q28;q11.2). METHODS: The study group included 10 women and 5 men with a median age of 64 years. All 15 patients had a diagnosis of T-PLL with t(X;14)(q28;q11.2). RESULTS: All 15 patients had lymphocytosis at initial diagnosis...

OBJECTIVES: Two-tiered serologic testing for Lyme disease is usually performed using an enzyme-linked immunosorbent assay (ELISA) as the first-tier test. The Quidel Sofia 2 Lyme test is a relatively new lateral flow method to provide more rapid turnaround time. We evaluated its performance in comparison to an established ELISA method. The test can be performed on demand rather than batching assays in a central laboratory. METHODS: We compared the Sofia 2 assay to the Zeus VlsE1/pepC10 IgG/IgM test in a standard two-tiered testing algorithm...

OBJECTIVES: Large B-cell lymphomas (LBCLs) are a heterogeneous group of lymphoid neoplasms whose molecular and cytogenetic profile has predictive and prognostic implications. The concept of double-hit lymphomas (DHLs) was recently updated in the fifth edition of the World Health Organization classification, with the exclusion of MYC and BCL6 rearranged tumors from the group. Now, DHLs are referred to as diffuse large B-cell lymphoma/high-grade B-cell lymphoma with MYC and BCL2 rearrangements...

OBJECTIVES: Targeted therapies for blastic plasmacytoid dendritic cell neoplasm (BPDCN) have presented a diagnostic dilemma for differentiating residual BPDCN from reactive plasmacytoid dendritic cells (pDCs) because these conditions have a similar immunoprofile, necessitating discovery of additional diagnostic markers. METHODS: Fifty cases of BPDCN involving bone marrow (26/50) and skin (24/50) as well as other hematologic malignancies (67) and nonneoplastic samples (37) were included...

OBJECTIVES: To explore the approach to the diagnosis of malignant serous effusion (SE) caused by angioimmunoblastic T-cell lymphoma (AITL). METHODS: The clinical, cytomorphologic, immunophenotypic, and molecular features of 6 patients were summarized. RESULTS: Clinically, SE caused by AITL was predominant in middle-aged and older male patients with multiple SEs and lymphadenopathy. Cytomorphology showed small to medium-sized, irregular lymphocytes with clear cytoplasm and mixed with various inflammatory cells and apoptosis...

OBJECTIVES: Malignant effusion is usually caused by metastatic carcinoma. Malignant lymphoma is often not included as a top differential diagnosis of malignant effusion. Here, we describe 3 cases of young female patients with no significant past medical history who presented with fluid overload and were diagnosed with high-grade B-cell lymphoma (HGBL). METHODS: We conducted histopathologic examination and immunophenotypic and cytogenetic analyses on three cases using immunohistochemistry, flow cytometry, fluorescence in situ hybridization (FISH), and karyotyping...