A causal link or coincidence? Anti-nephrin antibody-positive minimal change disease coexisting with neuroblastoma in a child

The combination of minimal change disease and solid tumors is uncommon, and its mechanism is often associated with immune disorders or metabolic abnormalities. Here, we describe an 8-year-old girl who presented with nephrotic syndrome characterized by edema and proteinuria as the initial symptoms. Chest imaging incidentally revealed the presence of a chest mass. Subsequently, a PET/CT scan ruled out the possibility of renal infiltration. Following surgical resection of the mass, pathological examination ultimately confirmed it as neuroblastoma. However, even after complete tumor resection, the nephrotic syndrome in the child did not show any relief. A kidney biopsy confirmed minimal change disease, and serum anti-nephrin antibodies were detected. After treatment with glucocorticoids, significant relief of edema, proteinuria, and hypoalbuminemia was observed in the short term. We report a case of newly diagnosed MCD associated with neuroblastoma. This rare case highlights the importance of integrating clinical manifestations, imaging, pathology, and anti-nephrin antibody testing to assist in diagnosis and treatment.