Dysregulated Repeat Element Viral-like Immune Response in Hepatocellular Carcinoma.

Purpose: Dysregulation of viral-like repeat RNAs are a common feature across many malignancies that are linked with immunological response, but the characterization of these in hepatocellular carcinoma (HCC) is understudied. In this study, we performed RNA hybridization (RNA-ISH) of different repeat RNAs, immunohistochemistry (IHC) for immune cell subpopulations, and spatial transcriptomics to understand the relationship of HCC repeat expression, immune response, and clinical outcomes.

Experimental Design: RNA-ISH for LINE1, HERV-K, HERV-H, and HSATII repeats and IHC for T-cell, Treg, B-cell, macrophage, and immune checkpoint markers were performed on 43 resected HCC specimens.

Nodular regenerative hyperplasia - An under-recognized vascular disorder of liver.

Introduction: Nodular regenerative hyperplasia (NRH) is a rare hepatic vascular disorder which is often associated with wide variety of systemic diseases. Intrahepatic microvascular injury and subsequent altered perfusion state leads to development of non-cirrhotic portal hypertension in many of these patients. Diagnosis of NRH often remains unsuspected clinically and liver biopsy is essential for the diagnosis and exclusion of fibrosis.

Epithelial to mesenchymal plasticity and differential response to therapies in pancreatic ductal adenocarcinoma.

Transcriptional profiling has defined pancreatic ductal adenocarcinoma (PDAC) into distinct subtypes with the majority being classical epithelial (E) or quasi-mesenchymal (QM). Despite clear differences in clinical behavior, growing evidence indicates these subtypes exist on a continuum with features of both subtypes present and suggestive of interconverting cell states. Here, we investigated the impact of different therapies being evaluated in PDAC on the phenotypic spectrum of the E/QM state.

Autoimmune Pancreatitis Type 2: Diagnostic Utility of PD-L1 Immunohistochemistry.

Background: Autoimmune pancreatitis (AIP) encompasses a heterogenous disease group that includes IgG4-related type 1 AIP and non-IgG4-related type 2 AIP. Clinically and on imaging, type 2 AIP mimics type 1 AIP, other forms of chronic pancreatitis and pancreatic ductal adenocarcinoma (PDAC); therefore, discriminatory markers may aid proper diagnosis. Herein, we examine the expression of PD-L1 and indoleamine 2,3-dioxygenase (IDO1) as a diagnostic tool to distinguish type 2 AIP from other forms of pancreatitis and PDAC.

MDM2 RNA In Situ Hybridization for the Diagnosis of Atypical Lipomatous Tumor: A Study Evaluating DNA, RNA, and Protein Expression.

The distinction of atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) from its benign counterpart, lipoma, may represent a challenge. MDM2 DNA amplification is used as the gold standard as MDM2 immunohistochemistry lacks specificity and sensitivity. Herein, we investigate the diagnostic utility of MDM2 RNA in situ hybridization (RNA-ISH) and compare the test with MDM2 immunohistochemistry and MDM2 DNA fluorescence in situ hybridization (FISH) in benign and malignant lipomatous neoplasms.

Morphologic Overlap Between Inflammatory Myofibroblastic Tumor and IgG4-related Disease: Lessons From Next-generation Sequencing.

Inflammatory myofibroblastic tumor (IMT), a locally aggressive neoplasm capable of metastasis, may show an immunoglobulin (Ig)G4-rich lymphoplasmacytic infiltrate. Prior reports suggest that storiform-fibrosis and obliterative phlebitis aid in the distinction of IMT from IgG4-related diseases. Herein, we highlight the morphologic overlap between the 2 diseases, and emphasize the importance of a multiplex fusion assay in the distinction of IgG4-related disease (IgG4-RD) from IMT.

Spindle and Round Cell Sarcoma With EWSR1-PATZ1 Gene Fusion: A Sarcoma With Polyphenotypic Differentiation.

The evolving classification of round cell sarcomas is driven by molecular alterations. EWSR1-PATZ1 fusion positive spindle and round cell sarcoma is one such new tumor entity. Herein, we report 2 EWSR1-PATZ1 fusion positive spindle and round cell sarcomas with overlapping histologic features and polyphenotypic differentiation.

Granulomatous Rosacea Versus Lupus Miliaris Disseminatus Faciei-2 Faces of Facial Granulomatous Disorder: A Clinicohistological and Molecular Study.

Granulomatous rosacea (GR) and lupus miliaris disseminatus faciei (LMDF) are 2 forms of facial granulomatous diseases. Although they show some morphological overlap, they have distinct clinical presentation. This study was performed to demonstrate the clinical and histological features of GR and LMDF and to establish their relationship to tuberculous etiology by molecular technique.

Granuloma Annulare-Like Granulomatous Reaction to Red Tattoo Pigment.

Cutaneous reactions to tattoos can be attributed either to trauma or to the exogenous pigment introduced into the skin. Red pigment is associated with a high sensitizing potential and is the most frequently implicated pigment inducing various types of histological reactions. Herein, we describe a patient with red tattoo pigment-induced granulomatous dermatitis that histologically revealed a very rare granuloma annulare-like reaction.

Spectrum of histopathological changes in patients with non-cirrhotic portal fibrosis.

Background And Aims: Non-cirrhotic portal fibrosis (NCPF) is a clinical disorder characterized by features of portal hypertension in the absence of significant fibrosis. It is one of the commonest causes of portal hypertension in India. This study aimed to analyze histomorphological spectrum of NCPF in detail.

In phyllodes tumour of the breast expression of c-kit but not of ALDH1A1 is associated with adverse clinico-pathological features.

Attempts at identification of an ideal prognostic/predictive biomarker in phyllodes tumour (PT) have not been fruitful so far. Studies evaluating c-kit expression in PT have shown contradictory results. Recently aldehyde dehydrogenase 1A1 (ALDH1A1) was proposed as a stem cell marker for malignant PT but its expression has not been studied in benign and borderline tumours.

Unusual manifestation of mucosal plasmacytosis mimicking erythema multiforme.

Mucosal plasmacytoses constitute a group of idiopathic inflammatory disorders, characterized by a dense infiltrate of plasma cells at the mucocutaneous junction without any recognizable dermatosis or neoplasm. We report an unusual clinical presentation of mucosal plasmacytosis presenting with hemorrhagic crusting of the lips, mimicking erythema multiforme.

IgG4-related inflammatory pseudotumor: A systematic review of histopathological features of reported cases.

Objectives: There is marked inconsistency in reporting the key features of IgG4-related inflammatory pseudotumor (IPT) cases. We aimed to analyze the various aspects of IgG4-related IPTs and to test the performance of the consensus criteria for their diagnosis.

Methods: PubMed database was searched for IgG4-related IPT cases.

Isolated benign primary cutaneous plasmacytosis in an adult Indian male.

Primary cutaneous plasmacytosis (PCP) is an uncommon reactive lymphoplasmacytic disorder of uncertain etiology. It has been mainly described in patients of Japanese descent, with only few reports in Caucasians and Chinese. We present a case of isolated benign PCP in a 45-year-old man, who clinically manifested with a localized ulcerated nodule overlying a hyperpigmented plaque on the upper back.

A Comparative Study of Inflammatory Myofibroblastic Tumors and Tumefactive IgG4-related Inflammatory Lesions: the Relevance of IgG4 Plasma Cells.

IgG4-related disease is a recently recognized systemic condition characterized by tumefactive lesions at various sites. Inflammatory pseudotumor (IPT), a tumefactive mass lesion with an unknown etiology, belongs to the spectrum of IgG4-related disease. Inflammatory myofibroblastic tumor (IMT), previously considered under the umbrella of IPT, is now classified as a clonal neoplasm.