Biomarkers of histologic severity in children with severe or atypical acute post-streptococcal glomerulonephritis.

BACKGROUND: Acute post-streptococcal glomerulonephritis (APSGN) is a common cause of acute kidney injury (AKI) in children; however, in a small subgroup, the presentation is one of rapidly progressive glomerulonephritis (RPGN) deteriorating kidney function associated with severe oligo-anuria or a mixed nephritic-nephrotic picture. This study reviewed potential clinical and laboratory factors which may assist the treating clinician to identify patients at high risk of severe disease. METHODS: All kidney biopsies for APSGN performed between 1996 and 2020 were obtained from a departmental biopsy database. Clinical and laboratory data were extracted from the patients' clinical records. Kidney biopsies were reviewed and scored independently by a renal histopathologist. RESULTS: Thirty of 53 (56.6%) patients had stage 3 AKI at initial presentation with a median estimated glomerular filtration rate (eGFR) 27 (IQR 11-41), falling to 20 ml/min/1.73 m2 (IQR 13.3-43) at time of biopsy. Patients who had either a pre-biopsy eGFR < 35 ml/min/1.73 m2 or a ≥ 25% fall in eGFR between admission and biopsy were more likely to have glomerular crescents (p = 0.004). Multivariate regression analysis and receiver operating curve showed the pre-biopsy eGFR most accurately predicted glomerular crescents (p = 0.047, ROC 0.757). There were no significant predictors of nephrotic proteinuria or nephrotic syndrome during the acute phase. CONCLUSIONS: Severe APSGN is associated with a pronounced reduction in eGFR. Calculation of eGFR in this small group of patients may assist in identifying which patient should have an urgent kidney biopsy to facilitate a more accurate clinical diagnosis and management plan.

Expanding the clinicopathological spectrum of succinate dehydrogenase-deficient renal cell carcinoma with a focus on variant morphologies: a study of 62 new tumors in 59 patients.

Most succinate dehydrogenase (SDH)-deficient renal cell carcinomas (RCCs) demonstrate stereotypical morphology characterized by bland eosinophilic cells with frequent intracytoplasmic inclusions. However, variant morphologic features have been increasingly recognized. We therefore sought to investigate the incidence and characteristics of SDH-deficient RCC with variant morphologies. We studied a multi-institutional cohort of 62 new SDH-deficient RCCs from 59 patients. The median age at presentation was 39 years (range 19-80), with a slight male predominance (M:F = 1.6:1). A relevant family history was reported in 9 patients (15%). Multifocal or bilateral tumors were identified radiologically in 5 patients (8%). Typical morphology was present at least focally in 59 tumors (95%). Variant morphologies were seen in 13 (21%) and included high-grade nuclear features and various combinations of papillary, solid, and tubular architecture. Necrosis was present in 13 tumors, 7 of which showed variant morphology. All 62 tumors demonstrated loss of SDHB expression by immunohistochemistry. None showed loss of SDHA expression. Germline SDH mutations were reported in all 18 patients for whom the results of testing were known. Among patients for whom follow-up data was available, metastatic disease was reported in 9 cases, 8 of whom had necrosis and/or variant morphology in their primary tumor. Three patients died of disease. In conclusion, variant morphologies and high-grade nuclear features occur in a subset of SDH-deficient RCCs and are associated with more aggressive behavior. We therefore recommend grading all SDH-deficient RCCs and emphasize the need for a low threshold for performing SDHB immunohistochemistry in any difficult to classify renal tumor, particularly if occurring at a younger age.

Utility of teledermatopathology for intraoperative margin assessment of melanoma in situ, lentigo maligna type: A 6 year community practice experience.

BACKGROUND: Achieving negative margins for melanoma in situ, lentigo maligna type can be challenging, particularly on cosmetically sensitive areas. OBJECTIVE: To assess the utility of intraoperative frozen section margin assessment using a teledermatopathology system in the treatment of head and neck lentigo maligna. METHODS AND MATERIALS: Over a 6 year period, 96 patients with lentigo maligna had surgical excisions. The margins were assessed intraoperatively with frozen sections prepared in the manner used in Mohs surgery. The surgeon guided the frozen section slides around the margin while a dermatopathologist assessed the margin remotely. RESULTS: In 2/96 (2.1%) cases, the safety margin was positive (frozen sections were false negative). In 1 further case (1%) there was a recurrence of the melanoma 13 months following the excision. CONCLUSION: The described method is effective in treating melanoma in situ, lentigo maligna type with clearance rates similar to previous studies for Mohs surgery.

A case of large cell neuroendocrine carcinoma of the bladder with prolonged spontaneous remission.

Large cell neuroendocrine carcinoma (LCNEC) of the urinary bladder are rare. We present a case of a 72-year-old man who presented with back pain and acute renal failure. Ultrasound showed a soft tissue mass in the base of the bladder causing bilateral ureteric obstruction. Subsequent biopsy of this mass demonstrated neuroendocrine carcinoma. He was commenced on neoadjuvant chemotherapy (carboplatin/etoposide) and proceeded to a radical cysto-prostatectomy. Histology revealed a LCNEC involving the bladder, T4a with invasion through to adipose tissue and posteriorly at perivesical resection margins. In addition, there was a Gleason score 9 prostatic adenocarcinoma, distinct from the neuroendocrine carcinoma. Following surgery, the patient developed gross local-regional recurrence and refused further systemic therapy. However, 1 year following referral to palliative care, a further CT-PET showed complete spontaneous remission of his disease. There are only few case reports of LCNEC of the urinary bladder therefore the pathogenesis and treatment protocol are still unclear. This case report highlights the unpredictable nature of this disease.

Outcome of severe acute post-streptococcal glomerulonephritis in New Zealand children.

Post-streptococcal glomerulonephritis (PSGN) is the commonest cause of severe acute glomerulonephritis in New Zealand children, with the majority (85%) of the patients being of either Pacific Island or Maori ethnicity. We have performed a retrospective study on 27 pediatric patients with acute PSGN. Of these patients, those with crescentic glomerulonephritis (n = 11) had a greater tendency (72.7%) for needing acute dialysis and were left with persistent urinary sediment abnormalities after a mean follow-up of 3.2 years (95% confidence interval 2.1-4.3). The efficacy of immunosuppression in the group with crescentic disease was uncertain. The severity of renal histopathological abnormalities as judged by the total biopsy score did not correlate with either presentation or eventual outcome. Severe childhood acute post-streptococcal glomerulonephritis, although uncommon, results in significant long-term renal morbidity, particularly among Maori and Pacific Island children.

The small world of the cerebral cortex.

While much information is available on the structural connectivity of the cerebral cortex, especially in the primate, the main organizational principles of the connection patterns linking brain areas, columns and individual cells have remained elusive. We attempt to characterize a wide variety of cortical connectivity data sets using a specific set of graph theory methods. We measure global aspects of cortical graphs including the abundance of small structural motifs such as cycles, the degree of local clustering of connections and the average path length. We examine large-scale cortical connection matrices obtained from neuroanatomical data bases, as well as probabilistic connection matrices at the level of small cortical neuronal populations linked by intra-areal and inter-areal connections. All cortical connection matrices examined in this study exhibit "small-world" attributes, characterized by the presence of abundant clustering of connections combined with short average distances between neuronal elements. We discuss the significance of these universal organizational features of cortex in light of functional brain anatomy. Supplementary materials are at www.indiana.edu/~cortex/lab.htm.