Fibroadenoma versus phyllodes tumor: a vexing problem revisited!

BACKGROUND: Fibroepithelial lesions of the breast include fibroadenoma (FA) and phyllodes tumor (PT). Fibroadenomas are benign while phyllodes tumor range from benign, indolent neoplasms to malignant tumors capable of distant metastasis. Our study was to determine the select cytologic features that can accurately distinguish FA from PT. METHODS: A retrospective review was performed of patients who had histopathology follow up of FA or PT and on whom a pre-operative fine needle aspiration was performed. Cytologic criteria i.e. epithelial component, stromal component and background cellularity were assessed. RESULTS: 46 FA and 24 PT were specimens were reviewed. Median age and tumor size for FA and PT were 23.0 and 39.0 years, and 2.0 and 5.0 cm, respectively. Univariate analysis and regression models based on generalized estimating equations revealed that large opened out, folded epithelial sheets, frayed and irregular stromal fragment contours, spindle stromal cell nuclei, spindle cell nuclei in the background and background cell atypia are significant cytological predictors of PT. The GEE regression model achieved 78.9% diagnostic accuracy (p <  0.001) in identifying PT based on cytological features. Median epithelial: stromal ratio was 3.4 and 2.6 for FA and PT, respectively. CONCLUSION: Presence of large, opened out, folded epithelial sheets, frayed and irregular stromal contours with spindle nuclei, background spindle cells and atypia can help distinguish PT from FA.

Characteristics, outcome and risk factors for mortality of paediatric patients with ICU-acquired candidemia in India: A multicentre prospective study.

BACKGROUND: The epidemiology, clinical profile and outcome of paediatric candidemia vary considerably by age, healthcare settings and prevalent Candida species. Despite these differences, few comprehensive studies are undertaken. This nationwide study addresses this knowledge gap. METHODS: 487 children who contracted ICU-acquired candidemia at 23 Indian tertiary care centres were assessed for 398 variables spanning demography, clinical characteristics, microbiology, treatment and outcome. RESULTS: Both neonates (5.0 days; range = 3.0-9.5) and non-neonatal children (7.0 days; range = 3.0-13.0) developed candidemia early after ICU admission. Majority of neonates were premature (63.7%) with low birthweight (57.1%). Perinatal asphyxia (7.3%), pneumonia (8.2%), congenital heart disease (8.4%) and invasive procedures were common comorbidities, and antibiotic use (94.1%) was widespread. C tropicalis (24.7%) and C albicans (20.7%) dominated both age groups. Antifungal treatment (66.5%) and removal of central catheters (44.8%) lagged behind. Overall resistance was low; however, emergence of resistant C krusei and C auris needs attention. The 30-day crude mortality was 27.8% (neonates) and 29.4% (non-neonates). Logistic regression identified admission to public sector ICUs (OR = 5.64), mechanical ventilation (OR = 2.82), corticosteroid therapy (OR = 8.89) and antifungal therapy (OR = 0.22) as independent predictors of 30-day crude mortality in neonates. Similarly, admission to public sector ICUs (OR = 3.62), mechanical ventilation (OR = 3.13), exposure to carbapenems (OR = 2.18) and azole antifungal therapy (OR = 0.48) were independent predictors for non-neonates. CONCLUSIONS: Our findings reveal a distinct epidemiology, including early infection with a different spectrum of Candida species, calling for appropriate intervention strategies to reduce candidemia morbidity and mortality. Independent factors identified in our regression models can help tackle these challenges.

Candida auris candidaemia in Indian ICUs: analysis of risk factors.

Objectives: To identify the risk factors associated with Candida auris candidaemia, as this fungus now poses a global threat. Methods: We performed a subgroup analysis of a previously reported study of 27 Indian ICUs. The clinical data of candidaemia cases due to C. auris and other Candida species were compared to determine significant risk factors associated with C. auris infection. Results: Of the 1400 candidaemia cases reported earlier, 74 (5.3%) from 19 of 27 ICUs were due to C. auris . The duration of ICU stay prior to candidaemia diagnosis was significantly longer in patients with C. auris candidaemia (median 25, IQR 12-45 days) compared with the non- auris group (median 15, IQR 9-28, P < 0.001). Based on logistic regression modelling, admission to north Indian ICUs [OR 2.1 (1.2-3.8); P = 0.012], public-sector hospital [OR 2.2 (1.2-3.9); P = 0.006], underlying respiratory illness [OR 2.1 (1.3-3.6); P = 0.002], vascular surgery [OR 2.3 (1.00-5.36); P = 0.048], prior antifungal exposure [OR 2.8 (1.6-4.8); P < 0.001] and low APACHE II score [OR 0.8 (0.8-0.9); P = 0.007] were significantly associated with C. auris candidaemia. The majority (45/51, 88.2%) of the isolates were clonal. A considerable number of isolates were resistant to fluconazole ( n = 43, 58.1%), amphotericin B ( n = 10, 13.5%) and caspofungin ( n = 7, 9.5%). Conclusions: Although C. auris infection has been observed across India, the number of cases is higher in public-sector hospitals in the north of the country. Longer stay in ICU, underlying respiratory illness, vascular surgery, medical intervention and antifungal exposure are the major risk factors for acquiring C. auris infection even among patients showing lower levels of morbidity.

On the emergence, spread and resistance of Candida auris: host, pathogen and environmental tipping points.

Over a decade ago, a multidrug-resistant nosocomial fungus Candida auris emerged worldwide and has since become a significant challenge for clinicians and microbiologists across the globe. A resilient pathogen, C. auris survives harsh disinfectants, desiccation and high-saline environments. It readily colonizes the inanimate environment, susceptible patients and causes invasive infections that exact a high toll. Prone to misidentification by conventional microbiology techniques, C. auris rapidly acquires multiple genetic determinants that confer multidrug resistance. Whole-genome sequencing has identified four distinct clades of C. auris, and possibly a fifth one, in circulation. Even as our understanding of this formidable pathogen grows, the nearly simultaneous emergence of its distinct clades in different parts of the world, followed by their rapid global spread, remains largely unexplained. We contend that certain host-pathogen-environmental factors have been evolving along adverse trajectories for the last few decades, especially in regions where C. auris originally appeared, until these factors possibly reached a tipping point to compel the evolution, emergence and spread of C. auris. Comparative genomics has helped identify several resistance mechanisms in C. auris that are analogous to those seen in other Candida species, but they fail to fully explain how high-level resistance rapidly develops in this yeast. A better understanding of these unresolved aspects is essential not only for the effective management of C. auris patients, hospital outbreaks and its global spread but also for forecasting and tackling novel resistant pathogens that might emerge in the future. In this review, we discuss the emergence, spread and resistance of C. auris, and propose future investigations to tackle this resilient pathogen.

Fine-Needle Aspiration Biopsy Cytopathology of Breast Lesions Using the International Academy of Cytology Yokohama System and Rapid On-Site Evaluation: A Single-Institute Experience.

INTRODUCTION: Breast cancer is rapidly emerging as the leading cause of cancer in Indian women. Robust cytopathology and histopathology services are required to tackle this growing burden. The use of rapid on-site evaluation (ROSE) and the International Academy of Cytology (IAC) Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy (FNAB) Cytopathology, which offers structured protocols, are expected to improve breast cytopathology reporting. METHODS: We retrieved the cytopathology slides, categorized them by the IAC Yokohama System and histopathology data of all the patients who had been investigated for breast lesions from September 2016 to December 2018, and compared the cytopathology and histopathology. Risk of malignancy (ROM) and performance metrics, like sensitivity, specificity, predictive values, accuracy, and area under the curve were computed. RESULTS: A total of 1,147 FNABs were evaluated, of which 442 (38.5%) underwent ROSE and 624 (54.4%) histopathology. Reported using IAC categories, our cohort recorded 4.9% inadequate, 65.3% benign, 7.8% atypical, 3.3% suspicious for malignancy, and 18.7% malignant lesions. The overall sensitivity and specificity for identifying in situ and malignant lesions were 99.1% and 99.3%, respectively, and were substantially improved by ROSE. ROSE improved the concordance between cytopathology and histopathology from 76.9% to 90.2%, by reducing inadequate (p < 0.001) cases. The ROM increased along a gradient from inadequate to malignant categories, with the gradient being sharpened by ROSE. The false negativity rate was 0.7% and false positivity rate 0%. CONCLUSION: Incorporating ROSE and the IAC Yokohama System for breast cytopathology reporting improves accurate diagnosis of breast lesions, prevents missed diagnoses, and provides reliable estimates of ROM. These protocols also aid in standardizing a reproducible system for monitoring and auditing of breast pathology services, identify areas that need strengthening, and improve training at pathology centers.

Scalar nanostructure of the Candida albicans cell wall; a molecular, cellular and ultrastructural analysis and interpretation.

Despite the importance of fungal cell walls as the principle determinant of fungal morphology and the defining element determining fungal interactions with other cells, few scalar models have been developed that reconcile chemical and microscopic attributes of its structure. The cell wall of the fungal pathogen Candida albicans is comprised of an amorphous inner skeletal layer of ß(1,3)- and ß(1,6)-glucan and chitin and an outer fibrillar layer thought to be dominated by highly mannosylated cell wall proteins. The architecture of these two layers can be resolved at the electron microscopy level, but the visualised structure of the wall has not yet been defined precisely in chemical terms. We have therefore examined the precise structure, location and molecular sizes of the cell wall components using transmission electron microscopy and tomography and tested predictions of the cell wall models using mutants and agents that perturb the normal cell wall structure. We demonstrate that the fibrils are comprised of a frond of N-linked outer chain mannans linked to a basal layer of GPI-proteins concentrated in the mid-wall region and that the non-elastic chitin microfibrils are cantilevered with sufficient lengths of non-fibrillar chitin and/or ß-glucan to enable the chitin-glucan cage to flex, e.g. during morphogenesis and osmotic swelling. We present the first three-dimensional nano-scalar model of the C. albicans cell wall which can be used to test hypotheses relating to the structure-function relationships that underpin the pathobiology of this fungal pathogen.

The Viscoelastic Properties of the Fungal Cell Wall Allow Traffic of AmBisome as Intact Liposome Vesicles.

The fungal cell wall is a critically important structure that represents a permeability barrier and protective shield. We probed Candida albicans and Cryptococcus neoformans with liposomes containing amphotericin B (AmBisome), with or without 15-nm colloidal gold particles. The liposomes have a diameter of 60 to 80 nm, and yet their mode of action requires them to penetrate the fungal cell wall to deliver amphotericin B to the cell membrane, where it binds to ergosterol. Surprisingly, using cryofixation techniques with electron microscopy, we observed that the liposomes remained intact during transit through the cell wall of both yeast species, even though the predicted porosity of the cell wall (pore size, ~5.8 nm) is theoretically too small to allow these liposomes to pass through intact. C. albicans mutants with altered cell wall thickness and composition were similar in both their in vitro AmBisome susceptibility and the ability of liposomes to penetrate the cell wall. AmBisome exposed to ergosterol-deficient C. albicans failed to penetrate beyond the mannoprotein-rich outer cell wall layer. Melanization of C. neoformans and the absence of amphotericin B in the liposomes were also associated with a significant reduction in liposome penetration. Therefore, AmBisome can reach cell membranes intact, implying that fungal cell wall viscoelastic properties are permissive to vesicular structures. The fact that AmBisome can transit through chemically diverse cell wall matrices when these liposomes are larger than the theoretical cell wall porosity suggests that the wall is capable of rapid remodeling, which may also be the mechanism for release of extracellular vesicles.IMPORTANCE AmBisome is a broad-spectrum fungicidal antifungal agent in which the hydrophobic polyene antibiotic amphotericin B is packaged within a 60- to 80-nm liposome. The mode of action involves perturbation of the fungal cell membrane by selectively binding to ergosterol, thereby disrupting membrane function. We report that the AmBisome liposome transits through the cell walls of both Candida albicans and Cryptococcus neoformans intact, despite the fact that the liposome is larger than the theoretical cell wall porosity. This implies that the cell wall has deformable, viscoelastic properties that are permissive to transwall vesicular traffic. These observations help explain the low toxicity of AmBisome, which can deliver its payload directly to the cell membrane without unloading the polyene in the cell wall. In addition, these findings suggest that extracellular vesicles may also be able to pass through the cell wall to deliver soluble and membrane-bound effectors and other molecules to the extracellular space.

Incidence, characteristics and outcome of ICU-acquired candidemia in India.

PURPOSE: A systematic epidemiological study on intensive care unit (ICU)-acquired candidemia across India. METHOD: A prospective, nationwide, multicentric, observational study was conducted at 27 Indian ICUs. Consecutive patients who acquired candidemia after ICU admission were enrolled during April 2011 through September 2012. Clinical and laboratory variables of these patients were recorded. The present study is an analysis of data specific for adult patients. RESULTS: Among 1,400 ICU-acquired candidemia cases (overall incidence of 6.51 cases/1,000 ICU admission), 65.2 % were adult. Though the study confirmed the already known risk factors for candidemia, the acquisition occurred early after admission to ICU (median 8 days; interquartile range 4-15 days), even infecting patients with lower APACHE II score at admission (median 17.0; mean ± SD 17.2 ± 5.9; interquartile range 14-20). The important finding of the study was the vast spectrum of agents (31 Candida species) causing candidemia and a high rate of isolation of Candida tropicalis (41.6 %). Azole and multidrug resistance were seen in 11.8 and 1.9 % of isolates. Public sector hospitals reported a significantly higher presence of the relatively resistant C. auris (8.2 vs. 3.9 %; p = 0.008) and C. rugosa (5.6 vs. 1.5 %; p = 0.001). The 30-day crude and attributable mortality rates of candidemia patients were 44.7 and 19.6 %, respectively. Logistic regression analysis revealed significant independent predictors of mortality including admission to public sector hospital, APACHE II score at admission, underlying renal failure, central venous catheterization and steroid therapy. CONCLUSION: The study highlighted a high burden of candidemia in Indian ICUs, early onset after ICU admission, higher risk despite less severe physiology score at admission and a vast spectrum of agents causing the disease with predominance of C. tropicalis.

Emergence of multidrug resistant acinetobacter blood stream infections in febrile neutropenia patients with haematological cancers and bone marrow failure syndromes.

Acinetobacter infections are fast emerging as a major nosocomial threat across the globe. With a predilection for blood stream infections in critically ill, immunocompromised patients, their presence is now being felt in febrile neutropenics with underlying malignancies and marrow failure. We aimed through this study to ascertain the current circulating pathogens and levels of antimicrobial resistance in blood stream infections in febrile neutropenia patients, with specific emphasis on elucidating acinetobacter and pseudomonas infections. Clinical and laboratory records of all consecutive neutropenic patients with underlying haematological malignancies and marrow failure, admitted to our AIIMS, New Delhi from April 2009 to March 2010 were analysed for blood stream infections, pathogen profiles and antimicrobial resistance. All clinical and microbiological variables were statistically analysed to elucidate potential risk factors, infection patterns and drug resistance trends. Of the 1,165 blood cultures investigated, 105 episodes of blood stream infections were microbiologically confirmed in febrile neutropenia patients. Gram-negative infections (n = 78, 72.9%) dominated with acinetobacter spp (n = 20, 18.7%) emerging as the most common pathogen. Acinetobacter and pseudomonas together were responsible for 42.9% of all blood stream infections. Both acinetobacter and pseudomonas displayed very high resistance to all five major classes of antibiotics, including multidrug resistance (90.0% and 76.9%) and ESBL production (90.0% and 84.6%), respectively. Comparison of infection patterns and resistance levels with reports over the past decade from this centre and other centres across the globe, revealed a striking increase in multidrug resistant acinetobacter blood stream infections in these patients. Multidrug resistant acinetobacter Infections are a fast emerging threat in febrile neutropenia patients and at this centre in general. Similar early trends from some Indian centres and neighbouring developing countries suggest grave concern. These emerging circulating pathogens and drug resistance patterns demand to systematically evaluate antibiotic and hospital infection policies and to sensitise all clinicians to curb this pathogen capable of rapid nosocomial spread.