Zahra Mirfeizi - Associated Professor of Rheumatology, Rheumatic Diseases Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Elham Atabati - Fellowship of Rheumatology, Mashhad University of Medical Science, Mashhad, Iran
Mohammad Reza Hatef - Associated Professor of Rheumatology, Rheumatic Diseases Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Kamila Hashemzadeh - Assistant Professor of Rheumatology, Rheumatic Diseases Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

IgG4-positive plasma cell infiltration has been observed in patients with other conditions, including retroperitoneal and mediastinal fibrosis, inflammatory pseudotumor of the lungs  and  liver,  Küttner  tumors,  and  interstitial  nephritis,  indicating that  these  diseases  and conditions collectively constitute a new disease concept known as IgG4-related disease . The aim of this study was to present a case of a typical IgG4 syndrome. The case presentation involves a 33-year-old man with a soft tissue mass (3 × 4 cm) on the right side of his frontal area which had enlarged over the space of a year. He had not experienced any allergic disorder, weight loss, night sweating, or anorexia, and did not smoke or use illicit drugs. On examination his vital signs were normal. He had no complains of fever, rash or urticaria. The soft, round mass in the right side of the frontal area had no pain and tenderness, redness, or discharge for the year. Other examinations gave normal results. He was then referred to a rheumatologist. In  further  laboratory work,  high  IgG4 level  (119.6; normal range:  5.9-86)  was detected and in histopathological studies, chronic inflammation, fibrosis, lymphomononuclear and eosinophilic infiltration with a dilated vascular network were reported.

IgG4-RD, chronic inflammation, Frontal mass