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Benign Collagen Rich Epithelioid NerveSheath Tumor in Cervical Spinal Cord: A

Case ReportBita Geramizadeh*,**♦, Simin Torabinejad**, Babak Pourabbas***

*Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran**Department of Pathology, Medical School, Shiraz University of Medical Sciences, Shiraz,

Iran***Department of Orthopedic Surgery, Orthopedic Research Center, Shiraz Medical

School, Shiraz University of Medical Sciences, Shiraz, Iran

Case ReportMiddle East Journal of Cancer; April 2016; 7(2): 97-100

♦Corresponding Author: Bita Geramizadeh, MDTransplant Research Center,Department of Pathology,Shiraz Medical School, ShirazUniversity of Medical Sciences,Shiraz, IranTel/fax: 00987136473238Email: [email protected]

IntroductionNerve sheath tumors are a

heterogeneous group of tumors thatconsist of schwannomas,neurofibromas and perineuromas.1Benign epithelioid nerve sheathtumors (BENST) are a group oftumors which are often diagnosticallychallenging because the epithelioidmorphology in a nerve sheath tumoris most commonly indicative of amalignant rather than benign tumor.2Most reported cases of BENST(epithelioid schwannoma) have arisenfrom soft tissue and skin.3

Here we report our experiencewith a young lady who presentedwith cervical pain, which turned outto be a BENST. To the best of ourknowledge this morphology in anerve sheath tumor in the cervicalspinal cord has not been reportedthus far.

Case reportA 36-year-old lady presented with

long standing neck pain. Her maincomplaint since at least 6 monthsago was cervical pain with noradiation. Her past medical history

AbstractTumors that originate from the nerve sheath comprise diverse groups -perineuroma,

neurofibroma and schwannoma. The epithelioid variant of these tumors is uncommonand mostly seen in malignant counterparts. Although this type of morphology is wellrecognized in peripheral nerve sheath tumors, its presence in the central nerves is rarelyreported. Very few cases of nerve sheath tumors have been reported with collagen-richstroma. Here we report an extremely rare case of nerve sheath tumor with epithelioidmorphology and collagen rich stroma. To the best of our knowledge this finding in thespinal cord has not been reported thus far.

Keywords: Epithelioid collagen rich nerve sheath tumor, Cervical spinal cord

Received: September 8, 2015; Accepted: November 2, 2015

Bita Geramizadeh et al.

was completely unremarkable. She has twohealthy children, with no specific familial historyexcept for a lumbar laminectomy in her fatherperformed several years ago.

Physical exam of the neck was remarkable fora non-radicular pain in the cervical to thoracicspine. Heart and lungs were completely normal.Both lower and upper extremity examinationswere normal. No skin or subcutaneous mass,lesion or change in color was detected.

Laboratory results were normal for biochemicaland hematologic analyses, with no abnormal tests.Molecular study for NF-1 showed the wild type.

Magnetic resonance imaging studies showed awell-demarcated capsulated hyposignal T1 andhypersignal T2 space occupying lesion in theright side of the spinal process and posterioraspect of the C7 that measured 4 cm in greatestdiameter (Figure 1).

The patient underwent surgery and an intraduralextramedullary tumor was easily dissected andexcised from the peripheral tissues. The pathologyspecimen was a well-defined encapsulated firmmass that had a creamy homogenous color. Nonecrosis or hemorrhage was detected.

Microscopic study of the mass showed acompletely heterogeneous appearance. The bulkof the tumor was composed of epithelioid cellsarranged mostly in sheets, with foci of rosetteformation (Figure 2a). The tumor cells were blandin appearance with no atypia or mitosis (Figure2b). There was no area of classic antoni-A or Bmorphology in the examined sections. Thespecimen was totally embedded. The tumor cellswere positive for S100 (Figure 2c) and vimentin,and negative for cytokeratin, epithelial membraneantigen (EMA), CD34, BCl2, smooth muscleactin (SMA), melan-A and CD99. There was nonecrosis or hemorrhage, but there were foci richin collagen (Figure 2d). P53 was negative andKi67 proliferative index was very low and lessthan 2% (Figure 2e). A diagnosis of BENST(collagen rich) or epithelioid schwannoma wasmade.

The patient spent an uneventful postoperativeperiod and left the hospital in excellent generalcondition. After 3 months she was doing well

and completely symptom-free, with no complaintsof neck pain.

DiscussionNerve sheath tumors are a heterogeneous group

of tumors which can be benign (benign nervesheath tumor) or malignant (malignant nervesheath tumor).3 Epithelioid morphology, althoughrare, is most commonly seen in malignant casesand is indicative of aggressive behavior. Thistype of morphology is well recognized inperipheral nerves of the soft tissue and skin,however it is very uncommon in central andcranial nerves.4

Epithelioid morphology in nerve sheath tumorsof the skin, subcutaneous and soft tissue wasreported in 33 cases by Laskinn et al. in 2005.3Epithelioid morphology has been rarely reportedin the cranial nerves; there have been 4 casesreported thus far. In a report by Tan et al. in 2004,no evidence of malignancy in clinicopathologicinvestigations were found.4

The most challenging, important point for thistype of tumor is the correct diagnosis and accurateexclusion of differential diagnoses. The goldstandard for confirmation of the diagnosis in anepithelioid nerve sheath tumor is immunohisto-chemistry (IHC). Diffuse positivity for S100 is avery important diagnostic clue.3

In cases with collagen rich stroma reportedby Jokinen et al.5, solitary fibrous tumor was a

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Figure 1. Magnetic resonance imaging (MRI) showed a well-demarcated encapsulated hyposignal T1 and hypersignal T2 spaceoccupying lesion in the right side of the spinus process and posterioraspect of C7.

Benign Collage Rich Epithelioid Nerve Sheath Tumor

very important differential diagnosis, which couldbe excluded with nonreactive CD34 and reactiveS100.5 Our case showed areas with collagen richstroma that resembled a solitary fibrous tumor,however this was excluded by IHC studies.

Other differentials such as meningioma andependymoma are also excluded by an IHC study.Soft tissue tumors such as fibroma and leiomyomaare excluded by negative CD34 and SMA results.

Another important point in this case was thefoci with rosette like morphology, which has beenreported by Goldblum et al. in 1994 in anepithelioid schwannoma with collagen rich stroma,as with our case.6 A number of authors have calledthis type of morphology a “neuroblastoma-likeepithelioid schwannoma”.7

In a nerve sheath tumor with epithelioidmorphology, malignancy should be diagnosedbased on hematoxylin and eosin (H&E) slides,confirmed by IHC.8

Presence of atypia, mitosis and necrosis arestrong evidences of malignancy which have notbeen found in our case. There should be a thoroughexamination of the tumor in order to locate anyevidence of malignant behavior.8 IHC for Ki67 isa reliable factor of the growth rate and possibilityof aggressive behavior; also p53 positivity can behelpful in this regard.8

Our case showed epithelioid morphology,rosette-like structures, and foci of collagen richstroma with no mitosis, atypia or necrosis. IHCshowed a low proliferative index with Ki67 andnegative P53. Follow up of our patient wasunremarkable.

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D. Non-reactive CD34.C. Reactive S100 in the nuclei of epithelioid cells.

B. Areas of the tumor show spindle-shaped cells with no atypia ormitosis (H&E; 400×). Note that the stroma of the tumor is rich incollagen.

Figure 2.Heterogeneous histopathology of the tumor according tohematoxylin and eosin (H&E) and immunohistochemistry (IHC)results.; A. Sections from the tumor show rosette-like structures(short arrow) and collagen rich stroma (long arrow) with no atypiaor mitosis (H&E; 250×) as well as epithelioid morphology.

Bita Geramizadeh et al.

In conclusion, nerve sheath tumors withepithelioid morphology are not always malignantand can be seen in peripheral, cranial and spinalnerve roots.

Conflict of Interest:No conflict of interest is declared.

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