Variant Hepatocellular Carcinoma Subtypes According to the 2019 WHO Classification: An Imaging-Focused Review.

The 2019 5th edition of the WHO classification of digestive system tumors estimates that up to 35% of hepatocellular carcinomas (HCCs) can be classified as one of eight subtypes defined by molecular characteristics: steatohepatitic, clear cell, macrotrabecular-massive, scirrhous, chromophobe, fibrolamellar, neutrophil-rich, and lymphocyte-rich HCCs. Due to their distinct cellular and architectural characteristics, these subtypes may not display arterial phase hyperenhancement and washout appearance, which are the classic MRI features of HCC, creating challenges in noninvasively diagnosing such lesions as HCC. Moreover, certain subtypes with atypical imaging features have a worse prognosis than other HCCs. A range of distinguishing imaging features may help raise suspicion that a liver lesion represents one of these HCC subtypes. In this review, we describe the MRI features that have been reported in association with various HCC subtypes according to the 2019 WHO classification, with attention given to the current understanding of these subtypes' pathologic and molecular bases and relevance to clinical practice. Imaging findings that differentiate the subtypes from benign liver lesions and non-HCC malignancies are highlighted. Familiarity with these sub-types and their imaging features may allow the radiologist to suggest their presence, though histologic analysis remains needed to establish the diagnosis.

An AI-assisted tool for efficient prostate cancer diagnosis in low-grade and low-volume cases.

Pathologists diagnose prostate cancer by core needle biopsy. In low-grade and low-volume cases, they look for a few malignant glands out of hundreds within a core. They may miss a few malignant glands, resulting in repeat biopsies or missed therapeutic opportunities. This study developed a multi-resolution deep-learning pipeline to assist pathologists in detecting malignant glands in core needle biopsies of low-grade and low-volume cases. Analyzing a gland at multiple resolutions, our model exploited morphology and neighborhood information, which were crucial in prostate gland classification. We developed and tested our pipeline on the slides of a local cohort of 99 patients in Singapore. Besides, we made the images publicly available, becoming the first digital histopathology dataset of patients of Asian ancestry with prostatic carcinoma. Our multi-resolution classification model achieved an area under the receiver operating characteristic curve (AUROC) value of 0.992 (95% confidence interval [CI]: 0.985-0.997) in the external validation study, showing the generalizability of our multi-resolution approach.

The Karakiewicz nomogram is the most useful clinical predictor for survival outcomes in patients with localized renal cell carcinoma.

BACKGROUND: Outcomes after surgical removal of localized renal cell carcinoma (RCC) are variable. There have been multiple prognostic nomograms and risk groups developed for estimation of survival outcomes, with different models in use for evaluating patient eligibility in ongoing trials of adjuvant therapy. The authors aimed to establish the most useful prognostic model for patients with localized RCC to guide trial design, biomarker research, and clinical counseling. METHODS: A total of 390 consecutive patients who underwent nephrectomy for sporadic localized RCC in a tertiary institution (1990-2006) with 65 months median follow-up were retrospectively evaluated. The Karakiewicz nomogram, the Kattan nomogram, the Sorbellini nomogram, and the Leibovich model were compared in predicting survival outcomes (overall survival, cancer-specific survival, and freedom from recurrence) using likelihood analysis, adequacy indices, decision curve analysis, calibration, and concordance indices. RESULTS: Overall, the Karakiewicz nomogram outperformed the Kattan nomogram, the Sorbellini nomogram, and the Leibovich model. Highly improved accuracy was seen using the Karakiewicz nomogram in survival prediction, using likelihood ratio analysis in bivariate models including the competing prognostic models. The Karakiewicz nomogram showed higher adequacy and concordance indices and improved clinical benefit relative to all other nomograms. All 4 models were reasonably calibrated. Exploratory comparisons of prespecified discretized Karakiewicz nomograms and the SORCE trial recruitment criteria (a discretized Leibovich model) of high-risk patients favored the discretized Karakiewicz nomograms. CONCLUSIONS: The Karakiewicz nomogram was shown to be superior to the other tested nomograms and risk groups in predicting survival outcomes in localized RCC. Routine integration of this model into trial design and biomarker research should be considered.

Genomic expression and single-nucleotide polymorphism profiling discriminates chromophobe renal cell carcinoma and oncocytoma.

BACKGROUND: Chromophobe renal cell carcinoma (chRCC) and renal oncocytoma are two distinct but closely related entities with strong morphologic and genetic similarities. While chRCC is a malignant tumor, oncocytoma is usually regarded as a benign entity. The overlapping characteristics are best explained by a common cellular origin, and the biologic differences between chRCC and oncocytoma are therefore of considerable interest in terms of carcinogenesis, diagnosis and clinical management. Previous studies have been relatively limited in terms of examining the differences between oncocytoma and chromophobe RCC. METHODS: Gene expression profiling using the Affymetrix HGU133Plus2 platform was applied on chRCC (n = 15) and oncocytoma specimens (n = 15). Supervised analysis was applied to identify a discriminatory gene signature, as well as differentially expressed genes. High throughput single-nucleotide polymorphism (SNP) genotyping was performed on independent samples (n = 14) using Affymetrix GeneChip Mapping 100 K arrays to assess correlation between expression and gene copy number. Immunohistochemical validation was performed in an independent set of tumors. RESULTS: A novel 14 probe-set signature was developed to classify the tumors internally with 93% accuracy, and this was successfully validated on an external data-set with 94% accuracy. Pathway analysis highlighted clinically relevant dysregulated pathways of c-erbB2 and mammalian target of rapamycin (mTOR) signaling in chRCC, but no significant differences in p-AKT or extracellular HER2 expression was identified on immunohistochemistry. Loss of chromosome 1p, reflected in both cytogenetic and expression analysis, is common to both entities, implying this may be an early event in histogenesis. Multiple regional areas of cytogenetic alterations and corresponding expression biases differentiating the two entities were identified. Parafibromin, aquaporin 6, and synaptogyrin 3 were novel immunohistochemical markers effectively discriminating the two pathologic entities. CONCLUSIONS: Gene expression profiles, high-throughput SNP genotyping, and pathway analysis effectively distinguish chRCC from oncocytoma. We have generated a novel transcript predictor that is able to discriminate between the two entities accurately, and which has been validated both in an internal and an independent data-set, implying generalizability. A cytogenetic alteration, loss of chromosome 1p, common to renal oncocytoma and chRCC has been identified, providing the opportunities for identifying novel tumor suppressor genes and we have identified a series of immunohistochemical markers that are clinically useful in discriminating chRCC and oncocytoma.

Multisystemic sarcoidosis-important lessons learnt from one of the great imitators.

We report a case of a woman who was admitted with a suspicion of metastatic malignancy of unknown primary origin. A few months prior to her admission, she presented to a rheumatologist with acute anterior uveitis, psoriasiform rashes and polyarthritis. A diagnosis of psoriatic arthropathy was made and she was treated accordingly. Soon after she presented with persistent back and right upper quadrant abdominal pain for which she had a CT scan done with evidence of hilar lymphadenopathy, liver hypodensities and lytic-sclerotic bone lesions. She was referred to our hospital for further investigations and management. After re-exploring her clinical presentation and further investigations (including a liver biopsy), a diagnosis of multisystemic sarcoidosis with ocular, reticuloendothelial, hepatic and skeletal involvement was made. The patient was started on systemic glucocorticoids and second line immunosuppressants and demonstrated significant clinical improvement with resolution of her liver granulomata on imaging and improvement in her back pain. The case illustrates the importance of a thorough clinical assessment, review of investigations and an open mind in the evaluation of a patient.

Metformin Inhibits Cellular Proliferation and Bioenergetics in Colorectal Cancer Patient-Derived Xenografts.

There is increasing preclinical evidence suggesting that metformin, an antidiabetic drug, has anticancer properties against various malignancies, including colorectal cancer. However, the majority of evidence, which was derived from cancer cell lines and xenografts, was likely to overestimate the benefit of metformin because these models are inadequate and require supraphysiologic levels of metformin. Here, we generated patient-derived xenograft (PDX) lines from 2 colorectal cancer patients to assess the properties of metformin and 5-fluorouracil (5-FU), the first-line drug treatment for colorectal cancer. Metformin (150 mg/kg) as a single agent inhibits the growth of both PDX tumors by at least 50% (P < 0.05) when administered orally for 24 days. In one of the PDX models, metformin given concurrently with 5-FU (25 mg/kg) leads to an 85% (P = 0.054) growth inhibition. Ex vivo culture of organoids generated from PDX demonstrates that metformin inhibits growth by executing metabolic changes to decrease oxygen consumption and activating AMPK-mediated pathways. In addition, we also performed genetic characterizations of serial PDX samples with corresponding parental tissues from patients using next-generation sequencing (NGS). Our pilot NGS study demonstrates that PDX represents a useful platform for analysis in cancer research because it demonstrates high fidelity with parental tumor. Furthermore, NGS analysis of PDX may be useful to determine genetic identifiers of drug response. This is the first preclinical study using PDX and PDX-derived organoids to investigate the efficacy of metformin in colorectal cancer. Mol Cancer Ther; 16(9); 2035-44. ©2017 AACR.

Primary malignant mixed Müllerian tumour (MMMT) of the vagina and review of the literature.

Primary malignant mixed Müllerian tumour (MMMT) of the vagina is a rare entity. We report a case of a 62-year-old woman who presented with a fixed and hard anterior vaginal wall mass with contact bleeding. She proceeded to have an anterior infralevator pelvic exenteration with urethrectomy and anterior vaginectomy, creation of an ileal conduit and bilateral lymph node dissection. Histopathological examination and immunohistochemistry confirmed the diagnosis of primary MMMT of the vagina. The patient was stage IVA at diagnosis. Despite chemotherapy and radiotherapy, she had progressive disease and eventually passed away at the age of 65 years.

Synchronous multicentric glioblastoma with PNET and O subtypes: Possible pathogenesis.

BACKGROUND: Glioblastomas (GBM) are highly infiltrative, cellular and mitotically active tumors with large histologic variations within and between tumours. Several subtypes have been described including the GBM with oligodendroglial differentiation (GBM-O) and primitive neuroectodermal tumour components (GBM-PNET). We report the first described case of a patient with synchronous multi-centric GBM-O and GBM-PNET components. CASE DESCRIPTION: A patient, who presented with a short history of progressive headache and difficulty with memory recall, was found on MRI imaging to have two intracranial lesions. These showed heterogeneous enhancement and were found in the left frontal and left temporal regions. The patient underwent gross total resection of these two lesions which were found to show GBM-O and GBM-PNET differentiations. CONCLUSION: Although tumour cell migration in the context of GBM is a well-recognized phenomenon, the traditional hypothesis is not able to satisfactorily explain this case of multicentric GBM whereby the two lesions demonstrate different cell origins. More current understanding of the migratory pathways from the subventricular zone provide an alternate and plausible pathway that fits our patient's unusual diagnosis.

Glottic neurofibroma in an elderly patient: a case report.

INTRODUCTION: Neurogenic tumors of the larynx are extremely rare, accounting for less than 1% of all benign laryngeal tumors. The lesions that have been described in current literature are located either in the supraglottis or subglottis, mainly affecting the pediatric population and associated with von Recklinghausen disease. STUDY DESIGN: Descriptive study of an unusual case of an isolated neurofibroma of the glottis in an elderly patient with no history of neurofibromatosis. DISCUSSION: We discuss preoperative clues to the diagnosis, our surgical experience, and propose a theory of its pathogenesis originating from encapsulated nerve structures within the vocal fold.

Comparison of the UCLA Integrated Staging System and the Leibovich score in survival prediction for patients with nonmetastatic clear cell renal cell carcinoma.

OBJECTIVES: To directly compare the models-the UCLA-Integrated Scoring System (UISS) and the Leibovich models-using various survival endpoints. Several Phase III trials of adjuvant therapy in renal cell carcinoma (RCC) have been initiated after advances in targeted therapy. To select patients at high risk of relapse and mortality, 2 aforementioned prognostic models have been incorporated into these trials. These models have not been compared previously. METHODS: A retrospective study of 355 patients with unilateral nonmetastatic clear cell RCC undergoing nephrectomy between 1990 and 2006 at the Singapore General Hospital was undertaken. Performance of the UISS and the Leibovich models, as well as corresponding trial inclusion criteria, was directly compared using log-likelihood statistics. Adequacy and concordance indices were also calculated. Study endpoints tested were overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). RESULTS: Likelihood ratio testing demonstrated a significant benefit in prediction when adding the Leibovich model to the UISS model in all outcomes tested, with no benefit using the converse approach (OS: P=.002 vs P=.27; CSS: P=.0001 vs P=.57; DFS: P=<0.0001 vs P=.30). Benefit was seen primarily in disease-free survival when adding the Leibovich trial criteria to UISS trial criteria, with no benefit using the converse approach (OS: P=.16 vs P=.27; CSS: P=.17 vs P=.11; DFS: P=.01 vs P=.26). CONCLUSIONS: Both the Leibovich model and trial criteria are superior to the UISS model and trial criteria, respectively, in estimating survival outcomes in patients with nonmetastatic clear cell RCC after nephrectomy.

A unique pair of monozygotic twins with concordant clear cell renal cell carcinoma: a case report.

INTRODUCTION: Genetic predisposition to clear cell renal cell carcinoma (ccRCC) has been linked to disorders such as von Hippel-Lindau (VHL) syndrome. While twin research is a classic approach for elucidating genetic and environmental contributions to disease, no monozygotic twin-pair concordant for ccRCC in the absence of VHL syndrome has been previously reported in the literature or in major twin registries. CLINICAL PICTURE: We describe a unique monozygotic twin-pair concordant for ccRCC, with discordant but early ages of onset of 25 and 38 respectively. Cytogenetic studies and direct sequencing for VHL gene mutations in the second twin proved unremarkable. CONCLUSIONS: This is the fi rst reported case of monozygotic twins concordant for ccRCC in the absence of VHL gene mutation. The early yet discordant, age of onset of disease in both twins suggests both genetic and environmental contributions to ccRCC.