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Case Report

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Magnetic Resonance Imaging of ParatesticularInflammatory Pseudotumor: A Case Report

Kursad Zengin,1 Nevzat Can Sener,1 Inan Alisir2

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IntroductionInflammatory pseudotumor (IPT) is a rare disease. The cause of

IPT is unknown. The most common site for IPT is the lung, but it isseen in almost every part of the human body. Although IPT is rare, itis the third most common mass involving paratesticular tissue afteradenomatous tumors and spermatic cord lipomas. The incidencepeaks in the third decade of life, and patients usually complain of anontender, gradually enlarging scrotal mass of 0.5 to 8 cm.1,2

The importance of the paratesticular IPT lies in the fact that it is oftenmistaken clinically as a malignant mass and results in orchiectomy. IPTmimics malignant tumors both clinically and radiologically.3 Ultrasono-graphic features of paratesticular IPTs do not yet allow a preoperativediagnosis.4 This prompted us to consider preoperative magnetic reso-

ance imaging (MRI), which may suggest the correct diagnosis in casesf fibrous pseudotumor. This allowed us to avoid unnecessary orchiec-omy in at least some cases of this benign entity.5

Case ReportA 46-year-old man presented with a 6-month history of a gradu-

ally enlarging, nontender right scrotal mass of approximately 3 cm indiameter. He had no previous history of local trauma. Routine serumand urine laboratory investigations, including concentrations of

1Diskapi Yildirim, Beyazid Teaching and Research Hospital, Urology Clinic, Ankara,urkey

2Fethiye State Hospital, Mugla, Turkey

Submitted: May 15, 2012; Revised: July 18, 2012; Accepted: Aug 16, 2012; Epub:Sep 18, 2012

Address for correspondence: Nevzat Can Sener, MD, Diskapi Yildirim BeyazidTeaching and Research Hospital, Urology Clinic, Ankara, Diskapi YB EAH, IrfanBastug Cad, Altindag/Ankara, Turkey

Clinical Pra● Paratesticular inflammatory pseudotumor (IPT) is a

very rare disease and mimics a tumoral process.● It is hard to exclude paratesticular pseudotumor from

malignant neoplasms of the testes in the preoperativedifferential diagnosis; therefore radical orchiectomymay be performed unnecessarily.

Clinical Genitourinary Cancer, Vol. 11, No.Keywords: Magnetic resonance

E-mail contact: cansener14@gmail.com

Clinical Genitourinary Cancer June 2013

beta-human chorionic gonadotropin, lactate dehydrogenase, andcarcinoembryonic antigen, were normal. On physical examination, awell-circumscribed, firm single nodule of 3 cm in diameter was pal-pated adjacent to the inferior border of the right testis; none of thelymph nodes were palpable. Scrotal Doppler ultrasonography re-vealed normal size and parenchymal echogenicity of both testis andepididymis. In the inferomedial part of the right hemiscrotum, avascularized hypoechoic extratesticular mass of 30 � 19 mm in di-ameter was noted. Clinical suspicion about the nature of the mass ledus to obtain an MRI, which suggested a benign 3.5 � 2.5 cm nodularparatesticular lesion in the inferoposterior neighborhood of the righttestis, with low signal intensity and minimal gadolinium enhance-ment on both T1- and T2A-weighted images because of the fibrousnature of the lesion (Figures 1-3). Bilateral minimal hydroceles werealso noted. These findings directed us to the diagnosis of IPT preop-eratively. The patient was prepared for surgical exploration undergeneral anesthesia. Surgical exploration revealed a 3.5 � 3 � 2 cmwhite-gray lobulated mass extending to the adjacent portion of thetunica vaginalis testis. Biopsy of the mass revealed a benign lesion, sothe mass was removed without radical orchiectomy.

Pathologic examination of the lesion revealed that microscopicallythe center of the mass showed wide collagenization and reducedcellularity, whereas cellularity increased peripherally and fascicles ofspindle cells were seen. Diffuse mixed inflammatory infiltrates ofpredominantly plasma cells and lymphocytes were present through-out the lesion. A few eosinophils, histiocytes, and neutrophils werealso present. There was no significant mitotic activity or nuclearatypia observed. The process extended throughout to the tunica vagi-nalis testis, but there was no sign of malignancy in that tissue either.On immunohistochemical examination, tumor cells showed positive

ice Points● Because the lesion is seen mostly in fertile men, dif-

ferential diagnosis is especially important to spare thetestis.

● The purpose of this study was to diagnose this benignlesion of the testis and paratesticular tissues with thehelp of magnetic resonance imaging (MRI).

4-6 © 2013 Elsevier Inc. All rights reserved.ing, Paratesticular tissues, Testis

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staining for vimentin, whereas they were negative for p53 and S-100;

1558-7673/$ - see frontmatter © 2013 Elsevier Inc. All rights reserved.http://dx.doi.org/10.1016/j.clgc.2012.08.006

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spindle cells were weakly stained with smooth muscle-specific actin.Ki-67 labeled fewer than 5% of the tumor cells.

On the basis of preoperative ultrasonography, MRI, and postop-erative immunohistochemical features, a paratesticular IPT was di-agnosed. The patient was followed for 1 year after surgery, and there

Figure 1 Magnetic Resonance Image of the Right Testis Withthe Lesion (T2-enhanced) (The arrow showsinflammatory pseudotumor [IPT] of the testis.)

Figure 2 Magnetic Resonance Image of the Right Testis Withthe Lesion (T1-enhanced). (The arrow shows IPT ofthe testis)

was no sign of tumor recurrence.

DiscussionIPT is an uncommon lesion that can appear in many organs. The

typical presentation of extratesticular IPT is a painless palpable tu-mor in the testicular adnexa. IPT is a benign, reactive, nonneoplasticlesion of spermatic cord, epididymis, or tunica caused by an inflam-matory reaction.6 Approximately 45% of IPTs are associated with a

ydrocele or hematocele, and 30% have a history of previous traumar epididymo-orchitis.7

Although it can be seen in different age groups, paratesticular IPTmost often appears in the third decade of life.2,7 It is rare but repre-sents the third most common benign tumor of the paratesticularregion after spermatic cord lipomas and epididymal adenomatoidtumors.7,8

The cause of IPT is unknown; various causes have been pro-posed, including a reparative process related to a delayed chronicresponse to remote or undetected trauma or infectious agentssuch as Epstein-Barr virus, Mycobacterium avium-intracellulareand herpesvirus 8, but none has been proved to cause paratesticu-lar IPT.9-12 In some mediastinal and abdominal IPTs, lesionshow a genetic clonal abnormality at the chromosome regionp23 near or within the anaplastic lymphoma receptor tyrosineinase (ALK) gene, suggesting a neoplastic change.13

Histologically, classic IPT is described as a lesion characterized byspindle cell proliferation in a loose, edematous myxoid stroma asso-ciated with a granulation tissue type and mixed acute and chronicinflammatory cells composed of lymphocytes, plasma cells, and eo-sinophils, with occasional neutrophils and mast cells.14 Immuno-

Figure 3 Magnetic Resonance Image of the Right Testis Withthe Lesion (T1-enhanced). (The arrow shows IPT ofthe testis)

markers prove the diagnosis of IPT. The spindle cells are reactive

Clinical Genitourinary Cancer June 2013 205

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MRI of a Paratesticular Inflammatory Pseudotumor

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with antibodies to vimentin, smooth muscle actin (SMA), and mus-cle-specific actin (MSA) in the majority of cases. Vimentin positivityis generally strong and diffuse, whereas SMA and MSA reactivitymay be focal or diffuse.15 In our patient, histologic examinationevealed strong positive staining for vimentin and weak staining forMA.

On an ultrasonogram, IPT mimics rhabdomyosarcoma, and theiagnosis is rarely made before surgical resection.4

The differential diagnosis of an IPT of the testicular tunics in-cludes solitary fibrous tumor, leiomyoma, neurofibroma, fibroma ofthe tunics, and idiopathic fibromatosis. Most patients with IPT un-dergo surgery because of the presence of a mass and the need toexclude a malignant process.2

IPT is difficult to distinguish from a malignant neoplasm, espe-cially in the testis. IPT can be hypoechoic or hyperechoic on ultra-sonography, and there is no specific appearance.16 Concomitant hy-drocele is frequent but nonspecific. Because of the nonspecific natureof the physical examination and ultrasonographic findings, it is notunusual for patients to undergo surgery; the chosen method of treat-ment in most patients in this fertile age group is radical orchiectomy.

Case reports using MRI are limited. MRI can be more definitive inmaking a preoperative diagnosis. IPTs have intermediate to low sig-nal intensity on T1-weighted images (similar to that of testis) and lowsignal intensity on T2-weighted images. When gadolinium contrastmaterial was given, there was little to no enhancement. Although thenumber of cases in the literature is small, these findings may prove tobe very specific for this mass.17

The most common disease to think of with a nontender testicularmass is testicular cancer. Our case was somewhat but not exactlywithin the limits for testicular cancer, and the physical examinationmade us suspect a paratesticular mass. To diagnose and clarify thenature of the lesion, we performed MRI. Without MRI for this raredisease, it is nearly impossible to diagnose the noncancerous lesions.With a noninvasive technique, such as MRI, benign lesions (IPT inour patient) can be differentiated from malignant tumors.

ConclusionParatesticular tumors such as IPT appear in the fertile years of

men. Because of the rare nature of these cases, diagnostic imaging is

Clinical Genitourinary Cancer June 2013

not performed regularly, and most patients are managed withorchiectomy.

We describe that MRI can be useful to differentiate IPT frommalignant tumors and can spare the testis.

DisclosureThe authors have stated that they have no conflicts of interest.

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