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Case Report

chwannoma of the Penis: Preservation ofhe Neurovascular Bundle

onah Marshall, Edward Lin, Vikram Dogra, and Robert Davis

chwannoma of the penis is a rare tumor. We report a case of penile schwannoma in a young man who was accuratelyiagnosed preoperatively with the help of gray-scale and color flow Doppler ultrasonography, and confirmed byagnetic resonance imaging. The tumor was successfully resected to completion, with preservation of the neurovascular

undles, preserving the patient’s erectile function. UROLOGY 70: 373.e1–373.e3, 2007. © 2007 Elsevier Inc.

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chwannomas are well-circumscribed, encapsulatedtumors that arise from cells of the peripheral nerve.These encapsulated masses are attached to the

erves, but they usually can be separated from them.1

chwannomas can arise from the peripheral nerves any-here in the body. Despite the rich enervation of theenital region, schwannomas of the penis are extremelyare.2 We present a case of penile schwannoma that wasccurately diagnosed by ultrasonography and was success-ully resected with complete preservation of the neuro-ascular bundles.

ASE REPORT29-year-old man presented with a lump on the penis of

t least 5 years’ duration. This mass had been growinglowly without any symptoms. He denied pain with erec-ions or sensory loss. At presentation, the lump hadrown to a size such that satisfactory intercourse was notossible (Fig. 1).

Ultrasonography revealed a 3 � 4 � 3-cm, heteroge-eous avascular mass that appeared to be of extracorpo-eal origin and had distorted both corpora without inva-ion. The blood supply to this mass appeared to arise fromhe dorsal artery of the penis. A differential diagnosis ofchwannoma, including leiomyoma and fibroma, wasonsidered. Magnetic resonance imaging confirmed theltrasound findings, demonstrating a mass external to theorpora (Fig. 2).

The patient was brought to the operating room foromplete resection of the mass. A subcoronal incisionas made, and dissection was performed down to Buck’s

ascia. The skin was degloved, exposing the tumor, withhe splayed neurovascular bundles overlying the massasily identified. Meticulous dissection was done, creating

rom the Departments of Urology and Imaging Sciences, University of Rochester,ochester, New YorkAddress for correspondence: Jonah Marshall, M.D., Department of Urology, Box

56, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642-0001.

e-mail: jonah_marshall@urmc.rochester.eduSubmitted: June 13, 2006; accepted (with revisions): May 14, 2007

2007 Elsevier Inc.ll Rights Reserved

flap down to Buck’s fascia and elevating the flap con-aining the neurovascular bundles on the right side. Anncision directly over the dorsal vein permitted dissectionf the dorsal vein free from the underlying structures.sing a vessel loop, the flap containing the dorsal vein

nd right neurovascular bundle was retracted to the left,xposing the tumor. The tumor had a smooth capsulend, after careful dissection, was enucleated from beneathhe dorsal vein (Fig. 3). At no time was the capsuleompromised. To maintain clear resection margins, aortion of the tunica albuginea was resected with thease of the tumor. There was no clear stalk. The massssentially “popped” out of the bed of resection. He-ostasis was achieved with electrocautery, the defect

n the tunica albuginea was repaired, Buck’s fascia waseconstituted, and the skin was closed with runninguture.

The mass was examined grossly and found to be homog-

igure 1. Penile mass. The mass was firm and fixed, andhe depth of invasion could not be determined by physicalxamination. It caused significant penile deformity and washe reason for patient presentation.

nously yellow, consistent with a schwannoma. Histologic

0090-4295/07/$32.00 373.e1doi:10.1016/j.urology.2007.05.003

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xamination confirmed the mass to be a schwannoma withharacteristic Antoni A and Antoni B fibers. The finaldentification was confirmed by positive S-100 staining.

All surgical margins were negative. The patient had a fulleturn of nocturnal erections at 1 month postoperatively. At

months postoperatively, the patient had normal erectile

igure 2. To further characterize the palpable penile masas performed. Magnetic resonance imaging scan demoorpus cavernosum in close proximity to glans penis (arrense compared with corpus cavernosum on sagittal T1-wmage.

igure 3. Neurovascular bundles identified and preserved uflap, consisting of Buck’s fascia and neurovascular str

esected in its entirety and excised as single, round specim

unction, no loss of sensation on the glans, and no indura- n

73.e2

ion at the site of resection, with an excellent cosmeticffect and no evidence of local recurrence.

OMMENTchwannomas are benign neurogenic tumors arising from

trasonography, followed by magnetic resonance imaging,ating well-circumscribed mass (arrow) along dorsum ofead). Lesion was (A) homogenously isointense to hypoin-ted image and (B) hyperintense on sagittal T2-weighted

2.5� magnification. (A) Neurovascular bundle isolated andres, retracted laterally to facilitate dissection. (B) Masswith minimal damage to corpora.

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eural crest-derived Schwann cells.1 They tend to be

UROLOGY 70 (2), 2007

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ncapsulated, with nerve fibers stretching around theerves. Although they can occur anywhere in the body,hey have a predilection for the head, neck, and flexorurfaces of the extremities.2–4 Although richly inner-ated, the penis is a very rare site of schwannoma occur-ence.2–8

Penile schwannoma is an extremely rare tumor, andnly 22 cases have been reported.2–11 In our patient, thereoperative imaging findings demonstrated no evidencef invasion of Buck’s fascia. An attempt was made tooth completely excise the tumor and preserve the penileeurovasculature, thereby preserving this patient’s erec-ile function.

Histologically, schwannomas are composed of a mix-ure of Antoni A and Antoni B fibers.1 Antoni A areasre composed of compact spindle cells with indistinctytoplasmic borders arranged in interlocking cellular fas-icles. Antoni B areas are regions of looser Schwann cellroliferation.1 This patient had both features promi-ently displayed.The other differential considerations in our patient

ncluded leiomyoma and neurofibroma. Leiomyomas arelow-growing, benign tumors characterized microscopi-ally by a predominance of spindle cells with rare mito-es.12 Leiomyomas are rarely found in the penis, withnly 2 cases reported.13,14 Neurofibroma is a benign tu-or arising from abnormal overgrowth of Schwann cells.hey are more difficult to dissect without damage to theerve compared with schwannomas. Neurofibromas areare and usually arise in the urinary bladder, although aew cases of penile neurofibroma have been reported.15

Local resection is the treatment of choice for localizedchwannoma.1–6 With complete resection, the rate of

ocal recurrence is extremely low. Our patient underwent

ROLOGY 70 (2), 2007

omplete resection with negative surgical margins andas doing well with no evidence of recurrence 6 monthsostoperatively.

eferences1. Cotran RS, and Kumar V: Robbins and Cotran, Pathologic Basis of

Disease: Peripheral Nerve Sheath Tumors. 7th ed. Philadelphia, WBSaunders, 2005, pp 1411–1413.

2. Mayersak JS, Viviano CJ, and Babiarz JW: Schwannoma of thepenis. J Urol 153: 1931–1932, 1995.

3. Jung DC, Hwang SI, Jung SI, et al: Neurilemmoma of the glanspenis: ultrasonography and magnetic resonance imaging findings.J Comp Tomogr 30: 68–69, 2006.

4. Suzuki Y, Ishigooka M, Tomaru M, et al: Schwannoma of the penis:report of a case and review of the literature. Int Urol Nephrol 30:197–202, 1998.

5. Jiang R, Chen JH, Chen M, et al: Male genital schwannoma,review of 5 cases. Asian J Androl 5: 251–254, 2003.

6. Marsidi PJ, and Winter CC: Schwannoma of penis. Urology 16:303–304, 1980.

7. Algaba F, Chivite A, Rodriguez-Villalba R, et al: Schwannoma ofthe penis: a report of 2 cases. J Androl 24: 651–652, 2003.

8. Sato D, Kase T, Tajima M, et al: Penile schwannoma. Int J Urol 8:87–89, 2001.

9. Pandit SK, Rattan KN, Gupta U, et al: Multiple neurilemmomas ofthe penis. Pediatr Surg Int 16: 457–460, 2000.

0. Hamilton DL, Dare AJ, and Chilton CP: Multiple neurilemmomasof the penis. Br J Urol 78: 468–469, 1996.

1. Kubota Y, Nakada T, Yaguchi H, et al: Schwannoma of the penis.Urol Int 51: 111–113, 1993.

2. Novick AC, and Campbell SC: Renal tumors, in Retick AB,Vaughan ED, Wein AJ, et al (Eds): Campbell’s Urology, 8th ed.2002, pp 2685–2685.

3. Bartoletti R, Gacci M, Nesi G, et al: Leiomyoma of the coronaglans penis. Urology 59: 445–446, 2002.

4. Leoni S, Parndi S, and Mora A: Leiomyoma of the prepuce. EurUrol 6: 188–189, 1980.

5. Ertas NM, Hucumengogly S, Demir Z, et al: Preputial neurofibroma

with hypospadias. Plast Reconstr Surg 106: 957–958, 2000.

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