RESUMEN
BACKGROUND: The literature describes a case of systemic lupus erythematosus (SLE) complicated with Castleman's disease (CD) and secondary paraneoplastic pemphigus (PNP). CASE PRESENTATION: A 12-year-old female presented with a neck mass, rash, arthralgia, and skin and mouth ulceration for 5 years were admitted. All blood cells were low. Multiple autoantibodies associated with SLE were positive. The pathology of the neck mass revealed the classical manifestations of CD. She was treated with prednisone, hydroxychloroquine, leflunomide, thalidomide, and dressings. Pathological examination of the skin revealed PNP. The neck mass was removed and continued to take antirheumatic drugs. At subsequent follow-up, the patient's disease status was stable and the skin mucosal lesion did not recur. CONCLUSION: The case of simultaneous SLE, CD, and PNP in children was rarely reported, and the correct diagnosis of the disease will help to take timely treatment.