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elvic Schwannoma Masquerading as Broad Ligament Myomaakesh Sinha, MD, Meenakshi Sundaram, MD*, Aparna Hegde, MD, andhaitali Mahajan, MD

rom the Bombay Endoscopy Academy and Center for Minimally Invasive Surgery (Beams Hospital), Mumbai, India (all authors).

BSTRACT Two cases of pelvic schwannoma appeared as broad ligament myoma. Laparoscopic myomectomy was planned for bothpatients in view of suspected broad ligament myoma. Intraoperative findings appeared to be degenerated myomas withsuggestion of malignancy. Both patients underwent complete tumor excision laparoscopically and had uneventful postop-erative recovery. Histopathologic examination confirmed them to be schwannomas. Solitary nerve sheath tumors such asbenign schwannomas arising in pelvic retroperitoneum are infrequently reported and difficult to diagnose preoperatively.Complete surgical excision is the treatment of choice. Benign retroperitoneal schwannomas in 2 patients primarily given thediagnosis of myoma were treated by laparoscopic excision. A MEDLINE search did not reveal reports of removing these

tumors laparoscopically. Journal of Minimally Invasive Gynecology (2008) 15, 217–219 © 2008 AAGL. All rights reserved.

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Benign schwannomas, also known as neurilemmomas,sually are slow-growing tumors arising from Schwannells of peripheral nerve sheaths. Because of its nonspecificlinical and imaging findings, preoperative diagnosis maye difficult. Two cases of pelvic schwannoma appeared asroad ligament myoma. Both patients underwent laparo-copic excision of the mass. The prognosis is excellent,xcision being curative in nearly every instance. This rarentity is often asymptomatic or has nonspecific symptomseading to misdiagnosis and prolonged morbidity.

ase Report 1

A 42-year-old woman complaining of abdominal pain.ltrasonography revealed a 74- � 71-mm isoechoic solid

esion in the right adnexa separate from the right ovaryuggestive of broad ligament myoma. Laparoscopic myo-ectomy was planned.On laparoscopy, a retroperitoneal 7- � 6-cm mass was

een near the right sacroiliac joint (Fig. 1). The peritoneumas opened by making a horizontal incision over the mass;

nd in view of a suspected myoma, enucleation was at-

he authors have no commercial, proprietary, or financial interest in theroducts or companies described in this article.orresponding author: Meenakshi Sundaram, MD, 674, 16th Cross Road,ehind Khar Gymkhana, Khar Pali, Khar (W), Mumbai 400 052, India.-mail: drmeena25@yahoo.com

ubmitted June 7, 2007. Accepted for publication September 22, 2007.

svailable at www.sciencedirect.com and www.jmig.org

553-4650/$ -see front matter © 2008 AAGL. All rights reserved.oi:10.1016/j.jmig.2007.09.009

empted. The mass was friable, appeared degenerated, andould not be enucleated (Fig. 2). It was removed by mor-ellating. As the base of mass was reached, a sudden gushf bleeding occurred. It was difficult to identify the vesselhat was bleeding. Clamps were applied laparoscopically inhe area to arrest bleeding ensuring that ureters were notncluded in clamp. Blood loss was 2 L. Once the clamp waspplied and bleeding controlled, the vessel was sutured.

The patient received 4 U of blood transfusion. The post-perative period was uneventful.

Histopathology showed fragments of benign spindle tu-or with areas of cellular degeneration. Tumor vessels

ppeared dilated. Characteristic nuclear palisading sug-ested benign schwannoma.

ase Report 2

A 50-year-old woman had abdominal pain and menor-hagia. Ultrasonography revealed a 55- � 60-mm solidesion in right adnexa suggestive of broad ligament myoma.n laparoscopy, a retroperitoneal 5- � 6-cm mass was seen

n the right broad ligament. The peritoneum was opened andnucleation attempted. The mass was degenerated and couldot be enucleated. Therefore, it was removed piecemealFig. 3). The mass was excised completely. The postoper-tive period was uneventful.

Histopathology showed characteristic nuclear palisading,ntoni A and B areas with Verocay body formation, andyaline change in hypocellular area suggesting benign

chwannoma (Fig. 4).

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218 Journal of Minimally Invasive Gynecology, Vol 15, No 2, March/April 2008

iscussion

Benign solitary schwannomas are uncommon soft-tis-ue tumors that can arise in peripheral, cranial, or sym-athetic nerves at virtually any anatomic site. Theseumors are thought to result from proliferation of peri-eural Schwann cells. Its origin from nerve sheath wasescribed [1]. They comprise 5% of all benign soft-tissueumors and have predilection for head and neck, andexor surfaces of upper and lower extremities [2].eeply seated schwannomas predominate in posteriorediastinum and retroperitoneum. Pelvic schwannoma is

are and accounts for less than 1% of all benign schw-nnomas [3]. Although an origin along nerves of retro-eritoneal space is not uncommon, these tumors rarelyppear as pelvic masses. In our cases, it may have orig-nated from peripheral fibers of sacral plexus.

Retroperitoneal schwannomas are usually larger andave a high tendency of undergoing spontaneous degener-

Fig. 1. Right retroperitoneal pelvic mass.

Fig. 2. Degenerated tissue seen in mass. M

tion and hemorrhage. Because the retroperitoneum is flex-ble and nonrestrictive, these tumors frequently attain aarge size before discovery. In our first case, the tumor wasompletely degenerated and difficult to remove in toto.acroscopically, schwannomas are solitary, well-circum-

cribed, encapsulated tumors [4]. Histologically, schwan-oma consists of compact cellular region with disposition inerocay body (Antoni type A tissue) or loose hypocellular,yxoid region with microcysts (Antoni type B tissue) [5].ecause of their slow growth and anatomic location, pelvic

chwannomas remain asymptomatic until they reach largeize and cause mass effect. This can lead to pain in lowerack and pelvis, and heaviness with urinary and digestiveymptoms caused by bladder and bowel compression. Sci-tic nerve impingement and pain caused by compression haslso been reported [6].

The diagnosis of pelvic schwannomas is very difficultecause of a lack of specific symptoms and pathognomonic

Fig. 3. Degenerated mass removed piecemeal.

ig. 4. Antoni A and B areas with Verocay body formation and hyalinehange in hypocellular area characteristic of schwannoma. (10 � 100

agnification.)

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219Sinha et al. Pelvic Schwannoma

maging features. Tumor size does not reflect degree ofggressiveness or malignant potential. Because of theirarger size, these tumors are likely to manifest secondaryegenerative changes. Complete surgical excision is thereatment of choice for schwannomas. In both our patients,e removed the mass completely by laparoscopy. Schwan-omas are usually benign but may very rarely undergoalignant transformation. Because malignancy cannot be

xcluded accurately preoperatively or even intraoperativelyith frozen section analysis, complete surgical resection is

ecommended [7]. Even an asymptomatically diagnosedatients should undergo surgical treatment as definitive di-gnosis cannot be obtained without histologic and immu-ohistochemical examination. As these tumors originaterom neuroectodermal cells, they stain positive for S-100rotein.

Large tumors tend to be highly vascular as was evident inur first patient [8]. Some authors have reported massivelood loss intraoperatively as a result of proximity of tumoro a pelvic venous plexus. Once suspected, it is better toeserve adequate blood for transfusion in case of emer-ency. Expertise in laparoscopic endosuturing skills is es-ential to tackle emergencies. Use of laparoscopic clampsan also be helpful in such situations to control torrentialleeding. Once a definitive diagnosis of schwannoma is

ade, after complete surgical excision, follow-up with pel-

ic sonography is adequate for further management. Bothur patients were symptomatically relieved after completexcision and are on regular follow-up. A thoroughEDLINE search did not reveal reports of removing these

umors laparoscopically.

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