Publications by authors named "Ming Liang Oon"

Peripheral T-cell lymphomas with gamma-delta phenotype (GDTCL) are rare lymphoid malignancies. Beyond the well-recognized entities of extranodal lymphomas with gamma-delta phenotype as defined by the 5th edition of the WHO Classification of Hematolymphoid Tumors and 2022 International Consensus Classification, there is a group of poorly-defined gamma-delta T-cell lymphomas with predominantly nodal presentation, termed as nodal GDTCL (nGDTCL). In this study, we present a series of 12 cases of EBV-negative nGDTCL, highlighting the clinical, histopathological and molecular features of this rare entity.

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Combined ganglioneuroma-schwannoma is an exceedingly rare tumor that has only been described in isolated case reports. We document a 64-year-old man with an incidentally discovered combined ganglioneuroma-schwannoma of the retroperitoneum that was intimately associated with sympathetic ganglia. We highlight the morphological and immunohistochemical findings of this rare tumor, and show evidence of its origin from sympathetic ganglia.

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Article Synopsis
  • * A case study on a 73-year-old man revealed a tumor initially thought to be a poorly differentiated carcinoma, but subsequent examination confirmed it as epithelioid angiosarcoma, with specific molecular characteristics identified through advanced testing methods.
  • * The findings highlight the need to consider epithelioid angiosarcoma as a differential diagnosis for high-grade salivary gland carcinomas, noting the potential for shared genetic alterations like TP53 mutations that complicate diagnosis.
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Adult rhabdomyoma is an uncommon benign mesenchymal neoplasm that most often occurs in the head and neck. We present a 70 year-old male with a swelling on the floor of the mouth. Subsequent excision of the tumor revealed a hitherto undescribed morphological variant of this tumor that features a predominance of clear cells, which on light microscopy may mimic other other clear cell tumours of the head and neck region.

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Article Synopsis
  • ChatGPT, an AI chatbot from OpenAI, was assessed for its effectiveness in diagnostic histopathology compared to human pathologists in a study that examined its collaborative potential.* -
  • The study revealed that ChatGPT's diagnostic accuracy was inferior to that of pathologists, and while its responses depended on the quality of prompts, it provided limited assistance in diagnosing cases.* -
  • Despite its shortcomings, pathologists acknowledged ChatGPT's utility as an advanced search tool, suggesting that future improvements in AI could enhance its role in histopathology.*
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Background: Crystal-storing histiocytosis (CSH) is a rare disorder which most commonly occurs in the setting of concurrent lymphoproliferative disease. Morphologically, it consists of aggregates of histiocytes containing eosinophilic crystalline material, which in most cases is composed of aggregated abnormal light chains.

Methods: Using histomorphology, immunohistochemistry and in situ hybridization, the authors characterize a rare case of orbital CSH associated with extranodal marginal zone (MALT) lymphoma and report for the first time the frozen section features of CSH.

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Ependymomas are glial neoplasms with a wide morphological spectrum. The majority of supratentorial ependymomas are known to harbor fusions, most commonly to . We present an unusual case of a 9-year-old boy with a supratentorial ependymoma harboring a noncanonical fusion.

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T-cell lymphomas arise from a single neoplastic clone and exhibit identical patterns of deletions in T-cell receptor (TCR) genes. Whole genome sequencing (WGS) data represent a treasure trove of information for the development of novel clinical applications. However, the use of WGS to identify clonal T-cell proliferations has not been systematically studied.

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Epstein-Barr virus (EBV)-positive T-cell and natural killer (NK)-cell lymphoproliferative diseases (EBV-TNKLPD) are a group of uncommon disorders characterised by EBV infection of T- and NK-cells. As a group, EBV-TNKLPD are more commonly encountered in Asians and Native Americans from Central and South America compared to Western populations. They encompass a spectrum of entities that range from non-neoplastic lesions such as EBV-associated haemophagocytic lymphohistiocytosis (EBV-HLH) to more chronic conditions with variable outcomes such as chronic active EBV infections (CAEBV) of T- and NK-cell type (cutaneous and systemic forms) and malignant diseases such as systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukaemia, extranodal NK/T-cell lymphoma, nasal-type, and primary EBV-positive nodal T/NK-cell lymphoma.

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Polo-like kinase-1 (PLK1) regulates the MYC-dependent kinome in aggressive B-cell lymphoma. However, the role of PLK1 and MYC toward proliferation in diffuse large B-cell lymphoma (DLBCL) is unknown. We use multiplexed fluorescent immunohistochemistry (fIHC) to evaluate the co-localization of MYC, PLK1 and Ki67 to study their association with proliferation in DLBCL.

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Metaplastic breast carcinomas are known to overexpress markers of epithelial-mesenchymal transition and cancer stem cells. We evaluated their immunohistochemical expression, correlating with clinicopathological parameters and survival outcomes. The study cohort comprised 63 cases diagnosed at the Department of Pathology, Singapore General Hospital.

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