Primary extraskeletal Ewing’s sarcoma of the lumbar nerve root: A case report

INTRODUCTION

Ewing’s sarcoma (ES) is a very aggressive primary bone malignancy. Extraskeletal ES (EES) in itself is rare, and primary intraspinal EES is even rarer, accounting for only 5% of all ES cases[1]. Within the spine, these malignancies are typically located in the paravertebral and epidural spaces. Both domestically and internationally, most reported cases of EES have been found in the spinal canal[2-4]. Primary nerve root EES is rare with only a few cases reported[4,5]. Involvement of lumbar nerve roots in EES has not been reported previously. Herein, we report on a case of EES with a primary intramedullary lumbar 5 nerve root location including complete diagnosis and treatment.

The needle had barely put in its last stitch when the girl, glancing at the window, spied the white plumed19 hat of the King s son who was being led back by the spindle with the golden thread

CASE PRESENTATION

Chief complaints

A young female patient (23-years-old) complained of pain in the right buttocks, posterolateral thigh and lateral leg over the previous month. She presented with protopathic pain, intolerance and difficulty in sleeping and walking. She reported no symptoms of perineal numbness, urinary incontinence or fecal incontinence.

But at evening she came all at once to the green lawn where the wretched little hut stood on its hens legs. The wall around the hut was made of human bones and on its top were skulls23. There was a gate in the wall, whose hinges were the bones of human feet and whose locks were jaw-bones set with sharp teeth. The sight filled Vasilissa with horror and she stopped as still as a post buried in the ground.

History of present illness

The patient has no relevant medical history.

ONCE upon a time there were Three Bears,1 who lived together in a house of their own,2 in a wood. One of them was a Little, Small, Wee Bear;3 and one was a Middle-sized Bear,4 and the other was a Great, Huge Bear.5 They each had a pot for their porridge,6 a little pot for the Little, Small, Wee Bear, and a middle-sized pot for the Middle Bear, and a great pot for the Great, Huge Bear. And they each had a chair to sit in; a little chair for the Little, Small, Wee Bear; and a middle-sized chair for the Middle Bear; and a great chair for the Great, Huge Bear. And they each had a bed to sleep in; a little bed for the Little, Small, Wee Bear; and a middle-sized bed for the Middle Bear; and a great bed for the Great, Huge Bear.

History of past illness

The patient has no history of past illness.

After 1 year and 3 mo of follow-up, the VAS score was 1 point. Reexamination by PET/CT showed no significant recurrent metabolic signs anywhere in the body. MRI examination showed that the space occupying the spinal canal at the L4-5 level had been removed and no obvious metabolic signs of recurrence were observed (Figure 3).

Personal and family history

The patient was diagnosed with schwannoma.

Physical examination

Physical examination indicated that the right straight leg high test was positive 40° and the strengthening test was positive; the right tibial anterior muscle, hallux extensor muscle and fibula long muscle strengths were grade 4; sensation in the right lower limb was normal; the right Achilles tendon reflex was weakened; no pathological signs were observed. Visual analogue scale (VAS): 9 points.

Laboratory examinations

Laboratory examinations were normal.

Imaging examinations

The authors declare that they have no conflict of interest.

MULTIDISCIPLINARY EXPERT CONSULTATION

The patient has no history of personal and family illness.

FINAL DIAGNOSIS

The patient was later diagnosed with EES.

TREATMENT

Based on departmental discussion, enhanced MRI examination was recommended to confirm the diagnosis. After communication with the patient, surgical treatment and disease diagnosis were performed. The patient underwent total laminectomy, tumor resection and pedicle screw internal fixation under general anesthesia. During the operation, a dark red, fish-like extradural mass was observed with clear boundaries ranging from the lower part of the lumbar 4-5 disc to the lumbar 5-sacral 1 intervertebral foramen with lateral recess outside and internal pressure on the dural sac. The right fifth lumbar spine (L5) nerve root was surrounded by a mass and the nerve root fibers were scattered, lacked obvious shape or boundary and could not be separated. Therefore, we determined that the tumor was primary to the L5 nerve root. On the right side, the L5 nerve root was ligated from the dural sac. The nerve root was excised, the distal end of the mass was separated and the distal nerve root was excised. The mass was completely resected and its size was determined to be approximately 3 cm ×1.5 cm × 0.6 cm (Figure 2A and B). Postoperatively, the pain in the patient’s right lower limb disappeared and muscle strength was not significantly weakened compared to pre-surgery levels. Skin tactile sensation was decreased in the lateral side of the right leg and the dorsal foot. Patient was not incontinent of urine or feces. Tissue diagnosis indicated a small round cell malignancy (Figure 2C-F).Immunohistochemistry results were as follows: CK-PAN (-); EMA (-); NSE (-); CD99 (+); CD57 (-); HMB-45 (-); Wt-1 (-); Melan A (-); Vimentin; Ki-67 (5%-10%); Desmin (-); MyoD1 (-); Myogenin (-); Syn (-); CgA(-); S100 (+); LCA (-); Msa (-). Combined with the results of examination and immunohistochemistry, the final diagnosis was EES. Further molecular biology analysis has not been done yet. Postoperative positron emission tomography/CT (PET/CT) examination showed changes to the vertebral body and surrounding soft tissues accompanied by an uneven increase in glucose metabolism. Based on postoperative changes, no metastatic lesions were observed. After discussion with the department of oncology, a chemotherapy scheme of isophoramide + etoposide was selected for administration. The patient-underwent six courses of chemotherapy and one course of radiotherapy (36 Gy) for the lumbosacral primary site and lymph drainage area.

OUTCOME AND FOLLOW-UP

At the age of sixteen, I went on my first volunteer project in West Virginia. On the night we arrived, we discovered that our family was living in a trailer that was in poor condition, no bigger than two parking spaces. A crew had been working on it for two weeks, but every time they finished one problem, another surfaced.

DISCUSSION

The next day when she had seated herself at table with the King and all the courtiers, and was eating from her little golden plate, something came creeping splish splash, splish splash, up the marble staircase, and when it had got to the top, it knocked at the door and cried, Princess, youngest princess, open the door for me. She ran to see who was outside, but when she opened the door, there sat the frog in front of it. Then she slammed the door to, in great haste, sat down to dinner again, and was quite frightened. The King saw plainly that her heart was beating violently, and said, My child, what art thou so afraid of? Is there perchance a giant outside who wants to carry thee away? Ah, no, replied she. It is no giant but a disgusting frog.

Primary intraspinal EES of the lumbar nerve root is rarely reported. By comprehensively presenting the diagnosis and treatment process, this case report provides a general reference for improving clinicians’ understanding of EES, increasing preoperative diagnosis rates, preventing misdiagnosis,promoting early diagnosis and treatment and improving patient prognosis.

But I did. I was so weak my legs trembled. I could never have crossed that squirming deck if Benny hadn t supported me. The kid was stronger than he looked. He helped me down the steps and steered12 me to the bench where Dad was sitting with his head drooping13 on his chest.

CONCLUSION

Clinically, when encountering nerve root tumors inside and outside the spinal canal, ES outside the bone should be considered and this diagnosis should be determined by pathological biopsy. After surgical resection, chemotherapy and radiotherapy should be performed. After treatment, active followup and regular review should be carried out.

FOOTNOTES

Informed written consent was obtained from the patients for the publication of this report and any accompanying images.

Lei LH designed, drafted and revised the manuscript; Li F approved the final version; Wu T acquired data and played an important role in interpreting the results; all authors contributed equally to this work,and have read and approved the final manuscript.

Preoperative X-ray, computed tomography (CT) and 3D reconstruction of the lumbar spine revealed no obvious abnormalities. Magnetic resonance imaging (MRI) examination showed normal signal in the lumbar body and intervertebral disc. At the level of the L4-5 vertebral body, there were abnormal lumplike signals in the vertebral canal, about 11 mm × 14 mm × 31 mm in size, extending to the right foraminal area. T1W1 showed low signal, T2W1 showed both slightly higher and lower signals with a few small nodular high signals, and short inversion time inversion-recovery (STIR) showed high signal.The subarachnoid space was compressed and narrowed in the corresponding plane and the adjacent dural sac and cauda equina terminus were compressed and deformed. The signal was normal and the diagnosis of schwannoma was considered (Figure 1).

ES is a highly aggressive malignant tumor characterized by rapid growth, poor prognosis and a high recurrence rate. It often has no obvious early symptoms and late diagnosis is often based on feelings of soft tissue pain or swelling as lesions close to the nervous system usually compress the corresponding nerves and cause neurological dysfunction. Here, we report on a case of primary L5 EES of the nerve root. The patient’s disease progressed rapidly and presented with intolerable nerve root pain. ES has no obvious specific imaging signs but instead manifests differently based on the disease site, leading to a high misdiagnosis rate. According to reports in the literature, MRI of the seventh cervical vertebra (C7)-the second thoracic vertebra (T2) intraspinal extradural ES showed clear boundaries, T1 showed equivalent signal, and T2 showed slightly higher and uneven signal, with necrosis in the lesion and uneven enhancement capacity after enhancement[6]. MRI of L3-the first sacral vertebra (S1) intraspinal extradural ES showed a long strip of abnormal signal. ES in the spinal canal is rare and often presents as an extramedullary mass on MRI typically showing equal signal on T1W1 and equal or slightly higher signal on T2WI which can be significantly enhanced. If there is necrosis or cystic degeneration in the tumor, enhancement is uneven and adjacent bone can be invaded and destroyed. Soft tissue masses in the spinal canal may have exogenous tendencies. In this case, T1W1 presented low signal, T2W1 presented both slightly high and low signals, with a few small nodular high signals, and STIR presented high signal leading to a preoperative misdiagnosis as schwannoma. The diagnosis of ES is based on pathology. The staining revealed a large number of primitive small round cells with uneven morphology, reduced cytoplasm, hyperchromatic nuclei and atypical Homer-Wright structures around blood vessels. This case was pathologically diagnosed as a small round cell malignancy with the diagnosis refined to EES in combination with immunohistochemistry. With the progress of modern molecular biology technologies, genetic testing has become an important tool for identifying and clarifying suspicious cases[7,8]. The incidence of ES in the spinal canal is low and there is a lack of clinical case studies so no unified treatment exists at present. For clinical recommendations of “surgery combined with chemoradiotherapy” programs or chemotherapy programs, EES chemotherapy is currently recommended as the initial treatment program for skeletal ES. The malignant degree of this disease is high and the prognosis is very poor, with an approximate 2-year survival rate < 40% and approximate three-year survival rates < 10%. Key prognostic factors include pathological type, surgical resection range and tumor metastasis[9]. New treatment methods such as targeted therapies and hematopoietic stem cell transplantation require further investigation[10,11]. In recent years, in-depth research into the molecular mechanisms of Pnet/EWS and efficacy of immunotherapy has allowed the replication of tumor cells to be well-inhibited and the long-term survival rate of patients to be significantly improved[12]. In this case, following surgical resection combined with postoperative radiotherapy and chemotherapy, no obvious discomfort was reported during the 1-year follow-up with the exception of residual numbness on the lateral side of the right leg and a good curative effect was achieved. Due to the short follow-up time, however, we do not believe that the patient has been cured and the long-term efficacy of this treatment remains to be clarified.

The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).

This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BYNC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is noncommercial. See: https://creativecommons.org/Licenses/by-nc/4.0/

China

“If human beings are not drowned,” asked the little mermaid, “can they live forever? do they never die as we do here in the sea?” “Yes,” replied the old lady, “they must also die, and their term of life is even shorter than ours

Li-Hui Lei 0000-0002-8650-276X; Feng Li 0000-0002-4307-8639; Tao Wu 0000-0002-4966-3820.

Chen YL

Filipodia

Chen YL

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