Perivascular epithelioid cell tumour (PEComa): an unusual cause of painful defaecation.

Perivascular epithelioid cell tumours (PEComa) are rare tumours of mesenchymal origin. We report a 39-year-old patient who presented with painful defecation secondary to an anorectal mass. The diagnosis of anorectal PEComa was confirmed following excision and histopathological examination. We review the literature and discuss the management of this uncommon entity.

Native kidney biopsies in older adults: disease spectrum, long-term kidney and patient survival and safety.

PURPOSE: Patients undergoing kidney biopsy are increasingly older. We aimed to evaluate the clinical utility of kidney biopsy, long-term clinical outcomes, and safety of high-risk biopsies in older adults undergoing kidney biopsy in a multi-ethnic Southeast Asian cohort. METHODS: We performed a single-center retrospective study of older patients (age ≥ 60 years) who underwent native kidney biopsies between June 2011 and March 2015. The primary long-term outcome of interest was a composite of ESKD or death. The safety outcome of interest was post-biopsy bleeding in the high-risk subgroup, defined by serum creatinine > 150 µmol/l. RESULTS: Older adults accounted for 153 of 545 (28.1%) native renal biopsies performed. The median age of these older adults was 66.6 (IQR 63.0, 70.6) years. Kidney dysfunction was frequent and severe in this cohort, with 41.2% having eGFR < 30 ml/min/m2 and 71.2% having nephrotic-range proteinuria at presentation. A significant proportion (124 patients; 81.0%) had treatable diagnoses. Of these, 90 (72.6%) received immunosuppressive therapy. On Kaplan-Meier analysis, patients with pauci-immune glomerulonephritis (p = 0.004) and diabetic nephropathy (p = 0.005) were at a significantly increased risk of the composite outcome of ESKD or death. On multivariate analysis, older age and lower eGFR were independently associated with ESKD or death and ESKD alone. Lupus nephritis and diabetic nephropathy were independently associated with ESKD or death, while immunosuppressant therapy was associated with reduced ESKD alone. In the high-risk subgroup, post-biopsy bleeding occurred in 19 (22.8%) patients. Desmopressin use was not associated with reduced bleeding complications. CONCLUSION: Our study confirmed the utility of kidney biopsy in older adult patients for diagnosis and management, although risk counselling and close monitoring for bleeding complications is necessary.

Breast-related extranodal Rosai-Dorfman disease presenting as subcutaneous masses with thick hyperechoic rim, with review of the literature.

Rosai-Dorfman disease (RDD) is a rare, idiopathic histiocytic proliferative disorder. We report two cases of RDD related to the breast which showed common distinctive imaging characteristics which can help facilitate accurate diagnosis and appropriate management.

MeSsAGe risk score: tool for renal biopsy decision in steroid-dependent nephrotic syndrome.

BACKGROUND: A lack of consensus exists as to the timing of kidney biopsy in children with steroid-dependent nephrotic syndrome (SDNS) where minimal change disease (MCD) predominates. This study aimed at examining the applicability of a biomarker-assisted risk score model to select SDNS patients at high risk of focal segmental glomerulosclerosis (FSGS) for biopsy. METHODS: Fifty-five patients with SDNS and biopsy-proven MCD (n = 40) or FSGS (n = 15) were studied. A risk score model was developed with variables consisting of age, sex, eGFR, suPAR levels and percentage of CD8+ memory T cells. Following multivariate regression analysis, total risk score was calculated as sum of the products of odds ratios and corresponding variables. Predictive cut-off point was determined using receiver operator characteristics (ROC) curve analysis. RESULTS: Plasma suPAR levels in FSGS patients were significantly higher, while percentage of CD45RO+CD8+CD3+ was significantly lower than in MCD patients and controls. ROC analysis suggests the risk score model with threshold score of 16.7 (AUC 0.84, 95% CI 0.72-0.96) was a good predictor of FSGS on biopsy. The 100% PPV cut-off was >24.0, while the 100% NPV was <13.3. CONCLUSION: A suPAR and CD8+ memory T cell percentage-based risk score model was developed to stratify SDNS patients for biopsy and for predicting FSGS.

Analysis of T Cell Subsets in Adult Primary/Idiopathic Minimal Change Disease: A Pilot Study.

AIM: To characterise infiltrating T cells in kidneys and circulating lymphocyte subsets of adult patients with primary/idiopathic minimal change disease. METHODS: In a cohort of 9 adult patients with primary/idiopathic minimal change recruited consecutively at disease onset, we characterized (1) infiltrating immune cells in the kidneys using immunohistochemistry and (2) circulating lymphocyte subsets using flow cytometry. As an exploratory analysis, association of the numbers and percentages of both kidney-infiltrating immune cells and the circulating lymphocyte subsets with kidney outcomes including deterioration of kidney function and proteinuria, as well as time to complete clinical remission up to 48 months of follow-up, was investigated. RESULTS: In the recruited patients with primary/idiopathic minimal change disease, we observed (a) a dominance of infiltrating T helper 17 cells and cytotoxic cells, comprising cytotoxic T cells and natural killer cells, over Foxp3+ Treg cells in the renal interstitium; (b) an increase in the circulating total CD8+ T cells in peripheral blood; and (c) an association of some of these parameters with kidney function and proteinuria. CONCLUSIONS: In primary/idiopathic minimal change disease, a relative numerical dominance of effector over regulatory T cells can be observed in kidney tissue and peripheral blood. However, larger confirmatory studies are necessary.

Histopathological analysis of infiltrating T cell subsets in acute T cell-mediated rejection in the kidney transplant.

AIM: To compare the differential immune T cell subset composition in patients with acute T cell-mediated rejection in the kidney transplant with subset composition in the absence of rejection, and to explore the association of their respective immune profiles with kidney transplant outcomes. METHODS: A pilot cross-sectional histopathological analysis of the immune infiltrate was performed using immunohistochemistry in a cohort of 14 patients with acute T cell-mediated rejection in the kidney transplant and 7 kidney transplant patients with no rejection subjected to biopsy to investigate acute kidney transplant dysfunction. All patients were recruited consecutively from 2012 to 2014 at the Singapore General Hospital. Association of the immune infiltrates with kidney transplant outcomes at up to 54 mo of follow up was also explored prospectively. RESULTS: In comparison to the absence of rejection, acute T cell-mediated rejection in the kidney transplant was characterised by numerical dominance of cytotoxic T lymphocytes over Foxp3+ regulatory T cells, but did not reach statistical significance owing to the small sample size in our pilot study. There was no obvious difference in absolute numbers of infiltrating cytotoxic T lymphocytes, Foxp3+ regulatory T cells and Th17 cells between the two patient groups when quantified separately. Our exploratory analysis on associations of T cell subset quantifications with kidney transplant outcomes revealed that the degree of Th17 cell infiltration was significantly associated with shorter time to doubling of creatinine and shorter time to transplant loss. CONCLUSION: Although this was a small pilot study, results support our suspicion that in kidney transplant patients the immune balance in acute T cell-mediated rejection is tilted towards the pro-rejection forces and prompt larger and more sophisticated studies.