IgG4 paratesticular fibrous pseudotumor: Case presentation and literature review.

PFP with IgG-4 immunostaining is a rare paratesticular tumour. Pre-operative ultrasound scan and MRI usually confirm the benign nature of the paratesticular mass avoiding the need for radical orchiectomy. The final diagnosis is based on histology of the removed paratesticular tumour. FDG PET scan plays an important role in ruling out systematic IgG4-related disease (IgG4-RD). We describe a case of multiple paratesticular fibrous pseudotumors with IgG4 immunostaining, not associated with systemic IgG4 related disease.