2021-29/ July 19
Contributors: Laskhmi Agarwal, Sanjay Gandhi, Manmohan Agrawala

A man in his 40s presented with scrotal swelling for six months duration. USG revealed a 4 x 3 cm sized solid testicular mass. Serum germ cell markers were negative.


1. What is the correct diagnosis?

a. Fibromatosis

b. Leiomyoma

c. Inflammatory Myofibroblastic Tumor

d. Paratesticular Fibrous Pseudotumor, cannot rule out IgG4

e. Solitary Fibrous Tumor

Paratesticular fibrous pseudotumor, cannot rule out IgG4

Para testicular fibrous pseudo tumour (PFP) is a rare tumor-like lesion with unknown etiology. It usually arises under the tunica vaginalis. It is paucicellular and is composed of fibroblastic and myofibroblastic proliferation in a storiform fibrotic background and is accompanied by numerous lymphoplasmacytic infiltration, with or without obliterative phlebitis, and germinal center.

It should be differentiated from inflammatory myofibroblastic tumor (IMT). IMT is more cellular and is composed of fascicles of plump to spindled myofibroblasts with a scant lymphoplasmacytic infiltrate, in contrast to the paucicellular, sclerotic appearance and numerous plasma cells typical of IgG4 related disease. ALK expression can be utilized to confirm the diagnosis of IMT. Other histological mimickers include solitary fibrous tumor, leiomyoma, fibromatosis, fibroma of tendon sheath and benign peripheral nerve sheath tumors, which can be excluded by careful histological examination and proper immunohistochemical stains.

1. Klaus-Peter Dieckmann, Werner Jan Struss, Ulrich Frey, Martina Nahler-Wildenhain Dieckmann et al. Paratesticular fibrous pseudotumor in young males presenting with histological features of IgG4-related disease: two case reports. Journal of Medical Case Reports 2013, 7:225.

2. Jha A., Baidya J.L., Batajoo R. Paratesticular fibrous pseudotumor arising from tunica vaginalis. Nepal Med Coll J 11 (2009) 145–146.

3. Oliva E., Young R.H Paratesticular tumor-like lesions. Semin Diagn Pathol 17 (2000) 340–358.

4. Parker P.M., Pugliese J.M., Allen R.C. Benign fibrous pseudotumor of tunica vaginalis testis. Urology 68 (2006) 427.e417–429.

Lakshmi Agarwal (1), Sanjay Gandhi(2), Manmohan Agrawala (3)
(1)Pathology, Government Medical College Kota,Consultant Pushpadi Cancer Care Centre, Rajastan, India

(2)Pathology, Histoplus Diagnostics, Ahmedabad, Gujarat, India

(3)Surgery, Pushpadi Cancer Care Centre, Kota, Rajasthan, India


Paratesticular, Benign, Fibrosis, plasma cells, IgG4-related