Background: Data on the outcome and risk factors of pediatric patients with SARS-CoV-2 infection (COVID-19) following hematopoietic stem cell transplantation (HSCT) are limited. Objectives: We aimed to describe risk factors for a severe course and mortality. Method: In this nationwide study, data were collected retrospectively from 28 transplant centers. Results: One hundred ninety-six children [(63.8% male; median age 8.75 (IQR, 4.86-14.30)] who received allogeneic (n: 184, 93.9%) or autologous (n: 12, 6.1%) HSCT were included. The median time from HSCT to SARS-CoV-2 infection was 207.5 days (IQR, 110.2-207.5). The most common clinical manifestation was fever (58.2%), followed by cough (33.7%); 43 cases (21.9%) were asymptomatic. Lower respiratory tract disease (LRTD) and multisystem inflammatory syndrome in children (MIS-C) developed in 58 (29.6%) and 8 (4.1%) patients, respectively. Twenty-six patients (13.3%) required ICU admission. Nine patients died at a median of 17 days (min-max 1-33) after COVID-19 diagnosis, 6 of whom died due to the disease, with a COVID-19 lethality rate of 3.1%. The 6-week overall survival was 95.4% (95% CI 92.5-98.3). Multivariate analysis found that HSCT with a mismatched donor (OR, 8.98, p: 0.039) and LRTD (OR, 61.55, p: 0.001) were independent risk factors for ICU admission; MIS-C (OR, 9.55, p: 0.044) and lymphopenia (OR, 4.01, p: 0.030) at diagnosis were risk factors for mortality. Conclusion: Overall mortality was lower in children than in adult counterparts, and HSCT with a mismatched donor, lymphopenia, LRTD, MIS-C and ICU admission were important risk factors for adverse outcomes.

Autoimmune hemolytic anemia (AIHA) is a rare condition in children which differs from the adult form. It is defined by immune-mediated destruction of red blood cells caused by autoantibodies. Treatment depends on the type of AIHA, its severity and whether there is an underlying disorder. Rituximab is now the preferred second-line treatment for primary warm autoimmune hemolytic anemia (Waiha). Here, we present a 2-monthboy with wAIHA, resistant to steroids and cyclosporin A, who was successfully treated with rituximab. Our patient is one of the youngest cases in the literature.

Background: Ewing sarcoma (ES) is a rare malignancy, most commonly presenting as a bone tumor, histologically characterized by sheets of poorly differentiated cells with small, blue, round nuclei and scant cytoplasm. Ewing sarcoma that may originate from bone or soft tissue has an increased tendency to involve the axial skeleton, particularly the pelvis. Case Report: We presented a case of Ewing sarcoma originated from pubis bone, who was underwent percutaneous nephrostomy due to external pressure on the bladder and ureter. Conclusion: We recommend placing optimal drainage, to each obstructed renal unit so treatment can be started as soon as possible