A pediatric case with hemolytic uremic syndrome associated with COVID-19, which progressed to end-stage kidney disease.

BACKGROUND: Hemolytic uremic syndrome (HUS) is a serious cause of acute kidney injury in children. There is a suggestion that coronavirus disease 2019 (COVID-19) may be a trigger for HUS. In this study, we present a pediatric case diagnosed with HUS associated with COVID-19, which progressed to end-stage kidney disease. CASE: A previously healthy 13-year-old girl with fever and vomiting was referred to our hospital. Laboratory investigations revealed direct Coombs-negative hemolytic anemia, thrombocytopenia and renal impairment accompanied by COVID-19 infection. Although anemia and thrombocytopenia showed improvement on the seventh day after admission, the renal impairment persisted. The histopathological findings of a renal biopsy were compatible with both HUS and COVID-19. One month later, the patient had a recurrence of HUS, again testing positive for COVID-19. Kidney function improved with plasma exchange therapy. Eculizumab treatment was recommenced after COVID-19 PCR became negative. Anemia and thrombocytopenia did not recur with eculizumab, while renal impairment persisted. Eculizumab was discontinued after three months when genetic analysis for HUS was negative. Subsequently, the patient was diagnosed with end-stage kidney disease. CONCLUSIONS: COVID-19 can be associated with HUS relapses, leading to chronic kidney disease. Further studies should investigate the mechanism of HUS associated with COVID-19.

Effective High-dose Interferon-α Therapy in a 13-Year-Old Girl With Erdheim-Chester Disease.

Erdheim-Chester disease (ECD) is a proliferative disorder of non-Langerhans histiocytes with a higher incidence in the fifth to seventh decades and rarer occurrence in the pediatric population. Although ECD typically involves bone, it can also affect the central nervous system, cardiovascular system, retro-orbital space, retroperitoneal space, and kidneys, lungs, and skin. A 13-year-old Syrian girl who presented with multisystemic involvement was diagnosed with ECD. The B-Raf proto-oncogene V600E mutation was not detected in ECD lesions. Response to the high-dose interferon-α therapy was excellent in this pediatric patient. In this article, pediatric ECD case reports are also reviewed.

Serrated lesions of the appendix: do they differ from their colorectal counterparts?

BACKGROUND/AIMS: The aim of this study is, therefore, to classify appendiceal serrated polyps in a large case series with respect to the recent World Health Organization classification using diagnostic criteria provided for colorectal serrated polyps. MATERIALS AND METHODS: A total of 960 appendix specimens diagnosed between 2005 and 2010 were reviewed retrospectively, and cases presenting with a polyp with serrated morphology were classified with reference to the recent World Health Organization criteria. Histologic criteria comprised architectural features of the crypts, including serration, branching, basal dilatation, inverted T- or L-shaped crypts together with cytologic features comprising a mucin pattern, dysplasia, in terms of pseudostratification and nuclear atypia, mitoses in the upper crypts, and cytoplasmic eosinophilia. RESULTS: A total of 71 cases (7.39%) were diagnosed as serrated polyps, including 36 (50.7%) hyperplastic polyps, 33 (46.48%) sessile serrated adenoma/polyps, and 2 (2.81%) traditional serrated adenomas. There were 32 males and 39 females with an age range of 2 to 82 years. Histology revealed that the majority of both hyperplastic polyps (63.9%) and sessile serrated adenomas/polyps (74.3%) involved the entire appendiceal circumference. Basal dilatation (94.3%), basal serration (94.3%), T-/L-shaped crypts (94.3%), and ectopic crypts (68.6%) were significantly more commonly observed in sessile serrated adenomas/polyps compared to hyperplastic polyps. Dysplasia was observed in 31.4% of sessile serrated adenomas/polyps, while hyperplastic polyps did not show dysplasia. CONCLUSION: The results of the present study suggest that appendiceal serrated polyps, despite bearing many similarities with their colorectal counterparts, may have some special features due to the anatomic uniqueness of the organ itself and also the polyps arising from its mucosal lining.