A Patient with 22q11.2 Deletion Syndrome Presenting with Systemic Skin Rash and Dermatopathic Lymphadenitis of Unusual Histology

Patient: Male, newborn Final Diagnosis: 22q11.2 deletion syndrome Symptoms: Congenital heart disease • eczema Medication:— Clinical Procedure: — Specialty: Immunology • Pathology • Pediatrics and Neonatology OBJECTIVE: Rare co-existance of disease or pathology BACKGROUND: Chromosome 22q11.2 deletion syndrome (22q11.2 DS) currently includes DiGeorge syndrome, conotruncal anomaly face syndrome, and velocardiofacial syndrome. We present the case of a male infant with 22q11.2 DS exhibiting generalized skin rash and dermatopathic lymphadenitis. CASE REPORT: The patient was born at 40 weeks of gestation with interruption of aortic arch, ventricular septal defect, and thymic defect. Fluorescence in situ hybridization method performed on buccal smears detected the deletion of 22q11.2. On day of life 33, diffuse erythema appeared on the entire body. A skin biopsy detected vacuolar interface dermatitis with superficial perivascular infiltration. Laboratory examinations revealed eosinophilia and hypocalcemia. Clinically, cutaneous inflammation was correlated with the abnormal immune response in 22q11.2 DS. On day of life 210, the patient died due to sepsis caused by Pseudomonas aeruginosa. An autopsy revealed lymph nodes swellings in the bilateral axillar and subclavicular areas and around the bilateral iliac arteries. Histology of the lymph nodes demonstrated sparse distribution of atrophic germinal centers surrounded by wide zones of proliferating spindle cells, as well as macrophages, Langerhans cells, and inter-digitating dendritic cells. Fontana-Masson staining revealed abundant melanin particles in the macrophages. Accordingly, we diagnosed this case as dermatopathic lymphadenitis. Interestingly, CD123 and CD56 double-positive spindle cells also proliferated around the germinal center. CONCLUSIONS: This case had an unusual histological feature of dermatopathic lymphadenitis. Considering the wide variety of unusual immune conditions in 22q11.2 DS, the lymph nodes in the systemic skin inflammation may exhibit an extraordinary histology of spindle cells proliferation.