Do we need to differentiate “true” inflammatory pseudotumor from IgG4-related disease?

Excerpt

Inflammatory pseudotumor is the pathologically non-neoplastic, chronic fibro-inflammatory granulomas with hyperplasia of fibroblasts and infiltration of immune cells such as lymphocytes, plasma cells, neutrophils and histiocytes [1]. Clinically, this disease presents with a progressive and destructive mass lesion. The common affected sites of inflammatory pseudotumor include the lungs, retroperitoneum, mediastinum, pelvis, liver, head and neck region. It is difficult to distinguish inflammatory pseudotumor from malignant diseases based on only blood and radiological findings. Thus, this disease is usually diagnosed with the pathological tissue examination. However, since the pathological findings for inflammatory pseudotumor are non-specific, clinicians often face difficulties in diagnosing and need to exclude the differential diagnosis before making the final diagnosis as “true” inflammatory pseudotumor. …