Publications by authors named "Kei-Shing Oh"

The standard treatment of choice for pleomorphic dermal sarcoma (PDS), a relatively uncommon soft tissue sarcoma and 1 morphologically similar to atypical fibroxanthoma, is wide local excision with close clinical follow-up. Studies regarding management of advanced/metastatic PDS with immune checkpoint inhibitors are limited as most STSs have historically been viewed as being immunologically inert. Contradicting this belief, in this report, we describe 2 cases of PDS with a robust host response.

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Artificial intelligence (AI) presents an opportunity in anatomic pathology to provide quantitative objective support to a traditionally subjective discipline, thereby enhancing clinical workflows and enriching diagnostic capabilities. AI requires access to digitized pathology materials, which, at present, are most commonly generated from the glass slide using whole-slide imaging. Models are developed collaboratively or sourced externally, and best practices suggest validation with internal datasets most closely resembling the data expected in practice.

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Background: Vivascope 2500 ex vivo confocal microscopy (EVCM) is an emerging optical imaging device that allows nuclear level resolution of freshly excised tissues. EVCM provides, rapid real-time pathological examination in many subspecialties of pathology including skin, prostate, breast, liver, etc. In contrast to traditional time-consuming frozen sectioning and histological analysis.

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Objectives: To improve documentation of blood product administration by assessing the completion status of blood transfusions. In this way, we can ensure compliance with the Association for the Advancement of Blood & Biotherapies standards and facilitate investigation of potential blood transfusion reactions.

Methods: This before-and-after study includes the implementation of an electronic health record (EHR)-based, standardized protocol for documenting the completion of blood product administration.

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Background: PRAME (PReferentially expressed Antigen in MElanoma) is a tumor-associated antigen that has been studied in various cutaneous melanocytic lesions. p16, on the other hand, has been proposed to aid in distinguishing between benign and malignant melanocytic neoplasms. Studies on the diagnostic utility of PRAME and p16 in combination in differentiating nevi from melanoma are limited.

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Objectives: The aim of this study is to analyze the prevalence of somatic mutations in and in malignant mesothelioma and their putative impact on protein properties.

Methods: Eighteen cases of malignant mesothelioma were retrieved from the archives and for next generation sequencing analysis of and genes. Variants were analyzed using Ensembl VEP17, Polyphen 2.

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Congenital infiltrating lipomatosis of the face (CILF) is a rare, congenital, nonhereditary facial overgrowth due to post-zygomatic activating mutations in gene. It is unilateral and involves hypertrophy of both the soft and hard tissue structures on the affected side of the face. This commonly results in early eruption of the teeth, hypertrophy of the facial bones, macroglossia, and proliferation of the parotid gland.

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Cutaneous non-Langerhans cell histiocytosis (NLCH) is a rare and biologically benign entity that can be broadly classified into two categories: xanthogranuloma and non-xanthogranuloma. The xanthogranuloma family is characterized by a proliferation of histiocytes with both macrophage and dendritic cell differentiation, negative BRAF mutation, and rare Touton-type giant cells. Molecular studies have reported that mutations involved in the MAPK signaling pathways are implicated in the pathophysiology of histiocytoses.

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Recently, we came across a patient with malignant melanoma and primary glioblastoma. Given this, we parsed the literature to ascertain the relationship, if any, between these 2 malignancies. We begin with a brief overview of melanoma and glioma in isolation followed by a chronologic overview of case reports and epidemiologic studies documenting both neoplasms.

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Background: Neonatal acute liver failure (NALF) is a rare and life-threatening condition. It causes bilirubin to accumulate to a dangerous level in the body, causing permanent damage to vital organs such as the brain and lungs. In many cases, the etiology of NALF remains unknown.

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Background: Hemangiomas are benign neoplasms of capillary proliferation that arise from a developmental anomaly where angioblastic mesenchyme fails to form canals. Most hemangiomas arise in the head and neck region, either superficially in the skin or deeper within endocrine organs such as the parotid gland. Parathyroid hemangiomas, however, are extremely rare, with only five cases previously reported in the literature.

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Brain tumors in adults may be infrequent when compared with other cancer etiologies, but they remain one of the deadliest with bleak survival rates. Current treatment modalities encompass surgical resection, chemotherapy, and radiotherapy. However, increasing resistance rates are being witnessed, and this has been attributed, in part, to cancer stem cells (CSCs).

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Background: Fibrosis, calcification, and ossification are histopathologic hallmarks of calcific aortic valve disease (CAVD), a leading cause of morbidity and mortality in the aging population. Cellular senescence contributes to a functional decay in chronic diseases by intensifying tissue remodeling and impairing tissue regeneration. We evaluated the expression of P16 and P53 as surrogate markers of senescence in CAVD.

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Collision tumors are rare entities that consist of at least two or more histologically and ontologically distinct tumor types within the same organ. It is still not well understood how collision tumors form; yet, three main theories have been proposed to explain the pathogenesis, including the "random collision effect," "field cancerization," and "tumor-to-tumor carcinogenesis." Collision tumors have been encountered in various body organs, including the lung.

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Collecting duct carcinoma is a rare neoplasm of the kidney, accounting for only 1-2% of renal tumors. These tumors arise from the principal cells of the renal collecting ducts of Bellini. The majority of patients have lymph node involvement and metastases to lungs, liver, bone, adrenal glands, and brain.

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Pyoderma gangrenosum (PG) is a skin disease characterized by painful ulcers that, when not appropriately treated, can lead to permanent disfigurement. Pyoderma gangrenosum has been observed in a multitude of autoimmune disorders such as rheumatoid arthritis, inflammatory bowel disease (IBD), and sarcoidosis (Feld et al. J Rheumatol.

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Hidradenocarcinoma (HC) is a rare malignant sweat gland tumor with metastatic potential primarily located in the head, neck, and trunk. We present an unusual case of a large lower extremity Clear Cell HC managed with surgical resection and adjuvant locoregional radiation after excluding lymph node involvement.

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Immunohistochemistry (IHC) is routinely performed in most laboratories, and other than purchase of commercially available antibodies, requires no additional equipment or reagents. As such, IHC is an accessible and relatively inexpensive test and one that can be performed quite quickly. This is in sharp contrast to genomic or mutational testing methodologies that are routinely "send out" tests as they require specialized equipment and reagents as well as individuals with expertise in the performance of the tests and analysis of the results, resulting in a prolonged turn-round-time and enhanced associated costs.

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PD-L1 is a transmembrane glycoprotein with an extracellular as well as an intracellular cytoplasmic domain. Physiologically, it plays a pivotal role in regulating T-cell activation and tolerance. Many tumor cells have exploited this regulatory mechanism by overexpressing PD-L1 in an effort to escape immunologic surveillance.

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