Retroperitoneal giant schwannomas: report on two cases and review of the literature

Retroperitoneal pelvic schwannoma: A rare case report and review of the literature

Schwannoma, typically a non-cancerous tumor originating from Schwann cells, seldom occurs in the retroperitoneal area. Its clinical manifestation varies, often remaining asymptomatic for an extended period until it enlarges, exerting pressure on neighboring organs. This article presents a unique instance of retroperitoneal pelvic schwannoma in a 75-year-old woman, initially presenting with unusual lower back discomfort. Imaging was used to characterize the tumor, and anatomopathological examination established the preoperative diagnosis of pelvic schwannoma and its benign nature. The clinical, imaging, and anatomopathological aspects of this pelvic schwannoma case are elucidated herein.

Huge adrenal schwannoma: a rare type of adrenal tumor, misconceived as adrenocortical carcinoma

Schwannoma is a benign and uncommon neoplasm arising from the neural crest cells. The most common tumor sites are the skin and subcutaneous tissue of the head and neck. Retroperitoneal schwannomas account for 1–3% of all schwannomas and are predominantly female. In particular, adrenal schwannoma is very rare, and due to its large size at the time of diagnosis, adrenal schwannoma is frequently misdiagnosed as adrenocortical carcinoma or pheochromocytoma. Adrenal schwannoma is difficult to distinguish it from other adrenal diseases based on imaging findings alone. In this report, we introduce the case of a huge left adrenal schwannoma.

Retrorectal schwannoma in a middle-aged female: A case report

INTRODUCTION AND IMPORTANCE

Primary sacral and presacral lesions are uncommon and pose a significant diagnostic dilemma. Retrorectal schwannoma is a benign primary presacral lesion that is extremely rare and presents with non-specific symptoms.

CASE PRESENTATION

A 42-years-old, female patient was admitted for lower-back pain for seven days. The retrorectal mass was detected on imaging, and she underwent laparoscopic excision. Pathological examination revealed a rare retrorectal schwannoma.

CLINICAL DISCUSSION

Retrorectal location of schwannomas is rare and the preoperative diagnosis is very difficult as the clinical features and the radiological features are non-specific. In addition, these tumors can be found incidentally on routine rectal or pelvic examinations. As these tumors are benign, encapsulated, and non-invasive, this entity has an excellent prognosis. Despite the tumors' rarity and variety, we concur with the literature that surgical management is required to obtain a clear diagnosis and avoid consequences such as malignant transformation.

CONCLUSION

Retrorectal Schwannoma presents a diagnostic and therapeutic challenge. Identification is important because surgical excision, either open or laparoscopic, is curative.

Total resection of presacral giant schwannoma via minimally invasive dorsal approach: illustrative case

BACKGROUND

Giant presacral schwannomas are extremely rare in neurosurgery. There are various approaches to the surgical treatment of symptomatic giant presacral schwannomas. The least traumatic is the one-stage surgery with a dorsal approach.

OBSERVATIONS

The authors describe a case of a 52-year-old male with pain in the sacral region and partial urinary dysfunction. A total tumor resection through a minimally invasive dorsal approach was performed, and anatomical and functional preservation of all sacral nerves with no postoperative complications was achieved.

LESSONS

The authors have shown the possibility of total tumor resection with a minimally invasive dorsal approach without the development of intra- and postoperative complications. Operative corridors that have been created by a tumor can be used and expanded for a minimally invasive dorsal approach to facilitate resection and minimize tissue disruption.

Para-adrenal schwannoma mimicking a giant adrenal lesion

A 57-year-old man was incidentally diagnosed with a 7 cm left-sided retroperitoneal mass. The mass was presumed to be arising from the left adrenal gland on a CT scan of the adrenal glands. Thus, a thorough workup ensued, looking into the possible functionality of the lesion. All investigations resulted in the negative. Subsequently, the patient was referred for surgery to fully characterise the tumour. Histology proved that the lesion was a benign retroperitoneal schwannoma with no relation to the adrenal gland.

Surgical Management of Symptomatic Lumbar, Sacral, and Lumbosacral Plexus Tumors: a Peripheral Nerve Unit Experience

OBJECTIVE

Data concerning the surgical treatment of lumbosacral plexus tumors (LSPTs) is scarce. This study aims to present our experience with a series of 19 patients surgically treated for symptomatic LSPTs at our institution.

METHODS

This is a retrospective study of 19 patients surgically treated for symptomatic LSPTs from 2011 to 2019. Clinical data were retrieved from medical records and consisted of age, gender, clinical presentation, location of the lesion, surgical approach, final histopathologic diagnosis, follow-up time, outcomes, and complications.

RESULTS

Nineteen surgical procedures were conducted. Thirteen patients were female and six, male. The median age of patients was 45 years (range 20 to 63 years). No patients harbored genetic syndromes. Surgical treatment appears to be correlated to the reduction of pain in patients with peripheral nerve sheath tumors (PNSTs), as assessed by visual analog scale (VAS). Sixteen patients did not present with new-onset deficits during follow-up (84.2%), two of whom recovered from their preoperative deficit. Four patients presented with postoperative weakness. The histopathological diagnoses were 11 schwannomas, four neurofibromas, three metastases, and one lymphoma.

CONCLUSIONS

LSPTs are rare. When surgical treatment is indicated, it usually requires multidisciplinary management. Surgery appears to be effective concerning the reduction of pain in PNSTs and may also recover neurological deficits. Iatrogenic neurological deficits are an evident risk, such that intraoperative multimodal monitoring should always be performed if available. In lesions involving the sacral plexus, we found it to be indispensable.

PET/CT and contrast-enhanced CT imaging findings in benign solitary schwannomas

OBJECTIVES

Imaging features of positron emission tomography (PET)/computed tomography (CT) and contrast-enhanced CT and pathological changes in benign solitary schwannoma were retrospectively analyzed, and the factors associated with high uptake of fluorodeoxyglucose (FDG) were examined.

METHODS

The PET/CT, contrast-enhanced CT, and pathological results of 58 cases of benign solitary schwannomas confirmed by surgery or biopsy were retrospectively analyzed. The association of each variable with the maximum standardized uptake value (SUVmax) was evaluated.

RESULTS

The SUVmax of the 58 benign schwannoma cases was 4.1 ± 2.1 (1.5-11.1). When the locations of schwannomas were divided into gastrointestinal system/heart/abdominal and pelvic cavities/thoracic wall (type-1 locations) and other sites (type-2 locations), the schwannoma location was significantly correlated with the SUVmax (r = 0.538, p =  0.000). The SUVmax values were 5.8 ± 2.4 and 3.3 ± 1.5, respectively (p =  0.000). Peritumoral lymphoid cuffs were observed in 7 cases, 4 of which were tumors of gastrointestinal origin, accounting for 80 % of the gastrointestinal schwannomas (4/5). The presence of peritumoral lymphoid cuffs was significantly correlated with the SUVmax (r = 0.456, p =  0.000). The location of the schwannoma was significantly correlated with the presence of peritumoral lymphoid cuffs (r = 0.640, p =  0.000). We found that a peritumoral lymphoid cuff is strongly correlated with the presence of regional lymphadenopathy. Among the 7 cases showing peritumoral lymphoid cuffs, 5 cases had the presence of peritumoral enlarged lymph nodes. The degree of enhancement was significantly correlated with the SUVmax (r = 0.556, p =  0.000).

CONCLUSIONS

Benign schwannomas originating from the gastrointestinal system/heart/abdominal location and showing the presence of peritumoral lymphoid cuffs or moderate and significant enhancement on contrast-enhanced CT were significantly associated with high FDG uptake. An accurate understanding of the factors associated with high FDG uptake can help reduce the misdiagnosis rate.

Update on MR Imaging of cystic retroperitoneal masses

OBJECTIVE

This article reviews the MRI appearance of cystic retroperitoneal (RP) masses.

CONCLUSION

Lymphangiomas are the most common RP cystic masses and typically appear simple; microscopic fat is a specific but insensitive finding. Location, internal complexity, and enhancement pattern suggest alternative diagnoses which range from normal anatomic variants to congenital abnormalities and importantly include benign, neurogenic, and malignant neoplasms. An approach to the MR imaging of cystic RP masses is presented.

Giant Presacral Schwannoma in Man: Report of a Case with Emphasis on Imaging Findings

BACKGROUND

Schwannoma is a tumor arising from peripheral nerve sheaths and commonly occurs in the head, neck, and upper and lower extremities. Schwannoma in the presacral space is relatively rare and is often misdiagnosed before pathologic diagnosis is made.

CASE DESCRIPTION

Here we discuss a case of giant presacral schwannoma in a 34-year-old man with an emphasis on imaging findings.

CONCLUSIONS

Solid and encapsulated, round or oval, with rich blood supply may be the characteristic imaging findings of presacral schwannoma, which may narrow the differential diagnosis of hypervascular pelvic lesions.

Surgical management of giant presacral schwannoma: systematic review of published cases and meta-analysis

OBJECTIVE

Giant presacral schwannomas are rare sacral tumors found in less than 1 of every 40,000 hospitalizations. Current management of these tumors is based solely upon case reports and small case series. In this paper the authors report the results of a systematic review of the available English literature on presacral schwannoma, focused on identifying the influence of tumor size, tumor morphology, surgical approach, and extent of resection (EOR) on recurrence-free survival and postoperative complications.

METHODS

The medical literature (PubMed and EMBASE) was queried for reports of surgically managed sacral schwannoma, either involving 2 or more contiguous vertebral levels or with a diameter ≥ 5 cm. Tumor size and morphology, surgical approach, EOR, intraoperative and postoperative complications, and survival data were recorded.

RESULTS

Seventy-six articles were included, covering 123 unique patients (mean age 44.1 ± 1.4 years, 50.4% male). The most common presenting symptoms were leg pain (28.7%), lower back pain (21.3%), and constipation (15.7%). Most surgeries used an open anterior-only (40.0%) or posterior-only (30%) approach. Postoperative complications occurred in 25.6% of patients and local recurrence was noted in 5.4%. En bloc resection significantly improved progression-free survival relative to subtotal resection (p = 0.03). No difference existed between en bloc and gross-total resection (GTR; p = 0.25) or among the surgical approaches (p = 0.66). Postoperative complications were more common following anterior versus posterior approaches (p = 0.04). Surgical blood loss was significantly correlated with operative duration and tumor volume on multiple linear regression (both p < 0.001).

CONCLUSIONS

Presacral schwannoma can reasonably be treated with either en bloc or piecemeal GTR. The approach should be dictated by lesion morphology, and recurrence is infrequent. Anterior approaches may increase the risk of postoperative complications.

Large retroperitoneal schwannoma: a rare cause of chronic back pain

Schwannomas are tumours that arise from Schwann cells of the peripheral nerve sheath and rarely occur in the retroperitoneum. We report a 45-year-old woman who presented with a 2-year history of continuous progressive right-sided lower back and dull flank pain radiating into her posterolateral thigh. Abdominal magnetic resonance imaging showed a homogenous soft-tissue tumour with thick capsular lining, which lay in the right retroperitoneum. The tumour was removed at surgery. A histological examination confirmed the diagnosis of benign encapsulated cellular schwannoma. Complete tumour excision should be regarded as the treatment of choice for benign retroperitoneal schwannomas. Successful treatment of these tumours requires thorough preoperative planning and a multidisciplinary approach.

Giant abdominoperineal malignant schwannoma: an unusual presentation and surgical challenge

Schwannoma is a benign tumor arising from the Schwann cells of peripheral nerves. These are usually benign but malignant transformation can occur in larger lesions. The definitive diagnosis of malignancy can only be made after final histopathological report. The literature reports large pelvic and perineal schwannomas with few being malignant. We report the first case of such giant malignant abdominoperineal schwannoma which was benign on initial biopsy but final histopathology revealed it to be malignant. In view of proximity of perineal and pelvic tumors to urogenital organs and pelvic nerves, such cases represent a challenge to surgical excision. This case brings to highlight another atypical presentation of such tumors.

Giant retroperitoneal ancient schwannoma: Is preoperative biopsy always mandatory?

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Giant schwannoma should be considered in the differential diagnosis of massive pelviabdominal masses.

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In the presence of severe symptoms, attempted surgical resection without a preoperative biopsy may be warranted.

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In such cases, total tumour resection, or at least debulking, will be beneficial.

INTRODUCTION

Schwannoma is the term given to tumours arising from Schwann cells of any nerve sheath. It may arise in the retroperitoneum, where it can attain enormous sizes and cause considerable diagnostic and therapeutic difficulties. A variety of incapacitating symptoms may arise, depending on its size alone and the related contagious organs.

PRESENTATION OF CASE

A 71-year-old female, who was incapacitated by a giant abdominal mass, associated with weight loss, immobility, general weakness and constipation. Radiologically, the presence of a huge pelviabdominal tumour was confirmed. A preoperative tissue diagnosis was entertained but omitted, and we resorted to direct surgical excision instead. During surgery, significant bleeding from the surrounding lumbar vessels was encountered, but it was controlled and the tumour was excised intact. Histopathologically, it showed the histologic features of ancient schwannoma.

DISCUSSION

In the patient presented here, who was rendered immobile by the tumour, total excision or at least debulking seemed appropriate, regardless of any biopsy result.

CONCLUSION

The diagnosis of retroperitoneal schwannoma and its variant “ancient schwannoma” should be considered when a huge pelviabdominal tumour is encountered. Although CT guided biopsy may be helpful in reaching a preoperative diagnosis, this might not change the decision for the need of total tumour excision or at least debulking, in the presence of incapacitating symptoms. With large tumours, the possibility of perioperative exanginating haemorrhage should be remembered and the necessary precautions activated.

Juxta-adrenal Ancient Schwannoma: A Rare Retroperitoneal Tumor

Retroperitoneal schwannoma is a rare tumor that is often misdiagnosed as malignancy due to a concerning appearance on cross-sectional imaging. Pathology and immunohistochemistry form the gold standard for diagnosis; as such, local excision is the treatment of choice for this disease. We present two cases of juxta-adrenal ancient schwannoma that were treated with adrenalectomy and discuss the current literature regarding this entity.

Robot-assisted excision of a large retroperitoneal schwannoma

Use of robotic technology is of benefit in performing minimally invasive retroperitoneal surgery.

Introduction:

There are few case reports of retroperitoneal tumor excision using the robotic technique. We describe a case of a 13 × 9 × 7–cm retroperitoneal schwannoma that was excised using robot-assisted surgery to provide a minimally invasive benefit to the patient.

Case Report:

A 45-year-old woman presented with a right paracaval retroperitoneal lump with well-defined margins displacing the inferior vena cava, the right kidney, the head of pancreas, and the duodenum. She underwent a robot-assisted excision of the tumor using the da Vinci Si HD surgical system using three robotic arms. The biopsy results revealed a well-encapsulated schwannoma diffusely positive for S100. The patient was discharged on the third postoperative day and was still doing well at 1-month follow-up.

Conclusion:

Use of robotic technology assists in providing minimally invasive benefits to the patient. It is a safe and effective technique for retroperitoneal surgery.

Diagnostic dilemma of a rare, giant retroperitoneal schwannoma: a case report and review of literature

Schwannoma is a benign tumour of peripheral nerve sheath. It usually arises from head, neck, and trunk. Retroperitoneal schwannoma is a rare entity, accounting for only 0.3–3% of total schwannomas. Majority of retroperitoneal schwannomas reported in literature have a diameter of 5 to 15 cm. Preoperative diagnosis is difficult due to low frequency, nonspecific clinical course, and nonspecific imaging features. Histology usually provides definitive diagnosis. Schwannomas are solitary, well-circumscribed, and noninvasive, so complete surgical excision provides good result. We report a case of a 23-year-old male, who presented with progressive abdominal distension and intermittent episodes of intestinal obstruction. CECT was suggestive of huge solid-cystic mass in abdominopelvic region. Image guided percutaneous aspiration revealed around 1 litre of frank pus and FNAC was suggestive of abscess. Exploratory laparotomy revealed a large 32 × 28 × 26 cm mass with solid and cystic components containing 1 litre of pus. Histological features of tumour were suggestive of benign schwannoma and immunohistochemistry for S-100 was positive. Postoperative recovery was uneventful. We report this case of a retroperitoneal schwannoma because of giant size, rare location, unusual presentation, and diagnostic dilemma.

Schwannoma with an uncommon anal location

Schwannomas are slow-growing mesenchymal neoplasms that arise from Schwann cells with low malignant potential. These uncommon neoplasms are nerve sheath tumors that arise at almost any anatomical site. The majority of schwannomas are benign, and few are malignant. The current study presents the rare case of an anal schwannoma that was successfully treated by surgery; there are few such cases previously reported in the literature. The patient was admitted to hospital following the identification of a mass incidentally. The tumor was so large that it compressed the tissue around it, although no symptoms were caused. The pre-operative clinical diagnosis was inconclusive in this case, and a final diagnosis was established based on radiographic and histopathological examination. The current study aimed to provide a possible differential diagnosis for such anally-located masses.

Unique surgical issues in the management of a giant retroperitoneal schwannoma and brief review of literature

Ancient Schwannoma, though benign, can cause diagnostic dilemma because of its clinical presentation and imaging features. We report the management of a giant retroperitoneal schwannoma in a 19-year-old young lady who presented with lower abdominal distension. CT scan reported a large heterogenous lesion in the abdominopelvic retroperitoneum (42 cm × 16 cm × 16 cm) as a malignant tumor. The unique problems we encountered were the enormous size, the location of major part of the tumor in the pelvis, the need for fertility preservation, the external iliac vessels stretching over the tumor making mobilization surgically demanding, and the prospects of neurological deficits. An en bloc resection of schwannoma with common iliac, external iliac and internal iliac veins, internal iliac artery, femoral and obturator nerves, and iliopsoas muscle was done maintaining oncological principles. External iliac artery that was cut to facilitate tumor mobilization was reanastomosed at the end of the procedure. Postoperatively patient had uneventful recovery with patchy sensory loss, foot drop, and quadriceps weakness which was rehabilitated with a foot drop splint and active physiotherapy.

Axillary schwannoma with extensive cystic degeneration

Schwannoma affect mainly head, neck, and flexor aspect of the limbs. Neurogenic tumors arising from the brachial plexus are rare and axillary schwannoma is extremely uncommon. Cystic degeneration is common in longstanding cases and which when aspirated may yield only macrophages or lymphocytes leading to false diagnosis of the case in spite of strong clinical suspicion. We report one such rare case of a solitary axillary schwannoma with extensive cystic degeneration, which was misdiagnosed on fine needle aspiration cytology and subsequently confirmed by the histopathological examination and immunohistochemistry.

Laparoscopic resection of an adrenal schwannoma

BACKGROUND AND OBJECTIVES

Schwannomas are tumors originating from Schwann cells of the peripheral nerve sheath (neurilemma) of the neuroectoderm. Rarely, schwannomas can arise from the retroperitoneum and adrenal medulla. We describe a case of a 71-y-old woman who presented with an incidentally discovered adrenal tumor.

METHODS

Ultrasound and computed tomography scans revealed a lesion with solid and cystic areas originating from the left adrenal gland. The patient underwent complete laparoscopic resection of the tumor and the left adrenal gland.

RESULTS

Histopathological examination and immunohistochemical staining of the excised specimen revealed a benign schwannoma measuring 5.5×5 3.7 cm. To our knowledge, few other cases of laparoscopic resection of adrenal schwannomas have been reported.

CONCLUSION

Because preoperative diagnosis of adrenal tumors is inconclusive, complete laparoscopic excision allows for definitive diagnosis with histological evaluation and represents the treatment of choice.

Giant presacral schwannoma presenting with constipation: a case report

Introduction

Schwannoma, otherwise known as a neurilemmoma, is a tumor arising from peripheral nerve sheaths. Although commonly noted in association with the eighth cranial nerve as intracranial acoustic neuroma, cases of schwannoma arising in other locations have been reported in the literature. These tumors usually cause symptoms as a result of their mass effect and, since they are benign, encapsulated and non-invasive tumors, complete surgical excision is considered curative.

Case presentation

We report the case of a 46-year-old Sri Lankan man who presented to our facility with recent onset of difficulty evacuating his bowels. He was noted to have a giant presacral schwannoma on magnetic resonance imaging scan. The mass was surgically excised with improvement of our patient’s symptoms. A subsequent histopathological examination confirmed the presence of a benign schwannoma.

Conclusions

Although schwannomas commonly occur in the extremities, a rare case of occurrence in the pelvis is reported here. Due to the limited space in the pelvis, the local mass effect may be the presenting feature of such a lesion and surgical excision is curative.

Retroperitoneal cystic schwannoma: A case report with review of literature

The occurrence of retroperitoneal schwannoma is uncommon and its presence may only be expressed by insidious onset of nonspecific symptoms such as vague abdominal pain. Imaging modalities like computed tomography and magnetic resonance imaging may demonstrate the tumor, but due to heterogeneity and degeneration in some tumors, it may mimic malignancy. So, fine needle aspiration cytology followed by tissue sampling through needle biopsies may be essential to confirm the diagnosis prior to the surgery. This case is reported for its rare clinical presentation, having duration of more than 40 years with cystic degenerative changes.

[A case of a retroperitoneal schwannoma presenting as hypermetabolic mass in PET-CT]

Schwannoma is a benign neoplasm of the Schwann cells of the neural sheath. Most schwannomas occur in the head and neck, and extremities and rarely in the retroperitoneal space. The differentiation of a schwannoma from other malignant tumor or benign tumor is very difficult on a preoperative examination with ultrasonography, computed tomography or magnetic resonance imaging. Furthermore, the lesion with increased fluorodeoxyglucose uptake in PET-CT cannot exclude malignant tumor. Therefore, this lesion needs surgical excision and a histological examination with immunohistochemical staining. We report a case of schwannoma occuring in the retroperitoneal space that incidentally discovered by PET-CT for health-check up. Pathologic confirmation by laparoscopic excision was done.

Giant sacral schwannoma: a report of six cases

Sacral and presacral schwannomas are often found incidentally, because they present with vague symptoms or symptomless. Schwannoma occurring in this area occasionally presents with enormous dimensions, known as a giant schwannoma. The tumor removal is a surgical challenge due to the difficult approach and abundant vascularity. The aim of this study is to review cases of giant sacral schwannomas focusing the surgical management and outcome. Six patients with sacral and presacral schwannoma were treated surgically. The patients included two males and four females, and the mean age was 47.8 years. All patients experienced pain at the time of presentation. The tumors were classified as intraosseous type in one case, dumb-bell type in four cases, and retroperitoneal type in one case. The tumors were removed with a piecemeal subtotal excision in three patients, a partial excision in two patients, and enucleation in one patient. The surgeries were performed by the combination of an anterior and posterior approach in three patients, a posterior approach in two patients, and an anterior approach in one patient. The mean surgical time was 7.8 hrs, and the mean blood loss was 2572 g. The tumor recurred in one patient after the partial excision and was removed completely in a second surgery. No patient, including the patient who underwent the second surgery, presented with pain and obvious neurological deficit at the final follow-up. The surgical treatment of the giant sacral schwannoma with a piecemeal subtotal excision can achieve a good outcome, avoiding unnecessary neurological deficit.

Ancient schwannoma of lumbar spine and review of the literature on paraspinal tumors, the role of preoperative biopsy: a case report

INTRODUCTION

Schwannomas are rare encapsulated tumors that derive from the nerve sheath and should be removed due to their infrequent, but existent possibility of malignancy.

CASE PRESENTATION

We report a case of a mass located in the L5 lumbar spine in a 42 year old man, presented with intermittent lumbar pain. Ultrasound, CT and MRI were used to examine the characteristics of the lesion. Fine needle aspiration showed cytologic characteristics of benign schwannoma and final histological diagnosis was ancient schwannoma. An extraperitoneal approach, through a left paramedian incision was used to approach the site of the mass. The lesion originated from the nerve root of the L4-L5 lumbar spinal space and a complete excision was achieved.

CONCLUSION

A great variety of tumors should be differentiated when a paraspinal mass is discovered, including neurogenic, neuroendocrine and vascular tumors, as well as malignancies, cystic and inflammatory masses. Fine needle aspiration is a useful and reliable tool in the preoperative evaluation of paraspinal masses. A review of the literature is also presented.

Strategy of surgical treatment of sacral neurogenic tumors

STUDY DESIGN

Assessment of different surgical approaches and procedures to remove different types of neurogenic tumors (Types I-IV).

OBJECTIVE

To aid surgeons faced with operating on a sacral neurogenic tumor by providing guidelines for determining the best surgical approach to use based on the way a neurogenic tumor presents.

SUMMARY OF BACKGROUND DATA

It is often difficult to determine the best surgical approach to use when operating on sacral neurogenic tumors. This retrospective study reports on the outcomes of patients with sacral neurogenic tumors and the surgical approach used in each case in order to better assess the most appropriate surgical approach and procedure to use with each tumor type.

METHODS

Between July 1998 and July 2006, 48 cases (18 males) with sacral neurogenic tumors were admitted and treated. Average age was 47 years old (range, 17-75). The average period of follow-up was 47 months. There were 41 cases with benign tumors and 7 cases of malignant tumors. Depending on how the tumor presented, 1 of 3 surgical approaches was used, an anterior approach (7 patients), a posterior approach (22 patients), or a combined anterior-posterior approach (19 patients).

RESULTS

For the cases of Type I and the cases of Type II and III in which tumors grew forward but were lower than S1 level, surgical resection of tumors required a simple posterior approach. The cases of Type II and III in which tumors grew forward and expanded higher than S1 level required a combined anterior-posterior approach. For cases of Type IV, a simple anterior approach for resection of tumors was used.

CONCLUSION

In surgical resection of sacral neurogenic tumors, surgical approach depends on the location and size of the tumors. Intraspinal tumors should be excised from a posterior approach. For giant neurogenic tumors that arise from the sacrum and involve the spinal canal, surgical resection should be done by a combined anterior-posterior approach. Giant presacral neurogenic tumors located below the S1 level can be removed by a posterior approach. The anterior surgical approach should be used for giant presacral neurogenic tumors that are located above S1 and do not involve the spinal canal.

Special problems encountering surgical management of large retroperitoneal schwannomas

Background

Retroperitoneal schwannomas are rare, usually benign tumors that originate in the neural sheath and account for only a small percentage of retroperitoneal tumors. The aim of this clinical study is to present our experience in managing retroperitoneal schwannomas with a review of the current literature and to point out the surgical technical difficulties we faced, due to the tumor's strange behavior that eroded the vertebra in two cases without causing malignant invasion.

Methods

We reviewed the medical files of 69 patients treated in our department for retroperitoneal tumors from January 1991 until December 2006. Five patients had retroperitoneal schwannomas according to pathology report.

Results

There were two male and three female patients, with a mean age of 56 years (range 44–67 years). All patients were asymptomatic and none suffered from von Recklinghausen disease. Imaging workup included ultrasonography, computed tomography and magnetic resonance imaging. One patient, after having a non-diagnostic computed tomography fine needle aspiration (CT-FNA), underwent exploratory laparotomy and incisional biopsy that established the diagnosis of schwannoma. After complete excision of the tumors, postoperative course was uneventful in all patients. Tumors' maximum diameter was 12.7 cm (range 7–20 cm). No recurrences were detected during the follow up period (6–75 months).

Conclusion

Preoperative establishment of diagnosis is difficult in case of retroperitoneal schwannomas, however close relationship of retroperitoneal tumors with adjacent neural structures in imaging studies should raise a suspicion. Complete surgical resection is the treatment of choice. Histology and Immunohistochemistry confirms the diagnosis.

Retroperitoneal giant schwannoma eroding lumbal vertebra: A case report with a literature review

A huge schwannoma, located in the retroperitoneal space, is found very rarely. The main purpose of this paper is to present the case of a giant retroperitoneal schwannoma which partly invaded L4 vertebral body. The secondary purpose is to summarize the case-report articles on retroperitoneal schwannomas. A circumscribed heterogenic tumour was revealed on transabdominal sonography. It extended into the right retroperitoneal space. CT and MRI revealed a paravertebral tumour in the size of 11 cm × 9 cm, which is causing a partial lysis of L4 vertebral body (15% of vertebral capacity), expanding intravertebral foramen and filling the right retroperitoneal space. A preoperative core needle biopsy was performed and a benign schwannoma was diagnosed. A complete surgical excision of the tumour was achieved by a two-step operation. During the first step, the neurosurgeons made L4 hemilaminectomy, facetectomy and a transverse process resection by posterior extended approach. The general surgeons excised the residual retroperitoneal part of the tumour by midline transabdominal approach 10 days later. The diagnosis of benign schwannoma was verified histochemically. There were no sign of tumour recurrence or spine destabilization at the six-month follow-up. In conclusion, although majority of giant retroperitoneal schwannomas can be completely removed performing one-step operation, a preoperative consideration about rationality of two-step operation should be mandatory when tumour destructs a part of vertebral body. Our case shows that the combined two stage complete surgical excision of a giant retroperitoneal schwannoma, eroding 15% of L4 vertebra’s osseous capacity, is effective and does not have any negative influence on spinal stability.

Benign retroperitoneal schwannoma presenting as colitis: A case report

We report a case of a patient presenting with clinical, radiological and endoscopic features of colitis due to a compressive left para-aortic mass. Total open surgical excision was performed, which resulted in complete resolution of colitis. Histopathology and immunohistochemistry revealed benign retroperitoneal schwannoma. These neural sheath tumors rarely occur in the retroperitoneum. They are usually asymptomatic but as they enlarge they may compress adjacent structures, which leads to a wide spectrum of non-specific symptoms, including lumbar pain, headache, secondary hypertension, abdominal pain and renal colicky pain. CT and MR findings show characteristic features, but none are specific. Schwannoma can be isolated sporadic lesions, or associated with schwannomatosis or neurofibromatosis type II (NF2). Although they vary in biological and clinical behavior, their presence is, in nearly every case, due to alterations or absence of the NF2 gene, which is involved in the growth regulation of Schwann cells. Both conditions were excluded by thorough mutation analysis. Diagnosis is based on histopathological examination and immunohistochemistry. Total excision is therapeutic and has a good prognosis. Schwannomatosis and NF2 should be excluded through clinical diagnostic criteria. Genetic testing of NF2 is probably not justified in the presence of a solitary retroperitoneal schwannoma.

Endoscopic resection of a presacral schwannoma. Case report

Presacral tumors are rarely found in adults. Resections via open abdominal or sacral approaches have been advocated traditionally as the preferred treatment for these tumors. The endoscopic surgical technique provides direct visualization of the presacral or retroperitoneal space. The authors report on a 67-year-old man who experienced difficulty in defecation off and on for 5 weeks, and recently he had suffered indistinct pain in the lower abdomen. The abdominal computed tomography scan revealed a 5.1 x 4.2-cm, homogeneous, low-density, well-defined mass arising from the left sciatic nerve abutting the left piriformis muscle, favoring a diagnosis of benign neurogenic tumor. Endoscopically guided resection was applied, with a favorable outcome. This procedure represents a less invasive approach that may be useful for benign retroperitoneal pelvic tumors.

Presacral tumours in adults

Presacral tumours represent a heterogeneous group of predominantly benign and occasionally malignant neoplasms. Due to the rarity of these tumours, their management is often performed in an ad hoc fashion and an algorithm for optimal treatment remains undefined. This review aims to present an overview of presacral tumours, focusing on their presentation, pathology, investigation and management.

Evaluation of perinephric, retroperitoneal schwannomas: case report and review of the literature

Schwannomas are tumors arising from the nerve sheath. Because of their infrequent occurrence, nonspecific symptoms, and lack of distinguishing radiologic features, schwannomas are most often diagnosed histologically after surgical excision. We report herein a case of a perinephric, retroperitoneal schwannoma which, after evaluation by computed tomography, magnetic resonance, and angiography, appeared to be a renal cell carcinoma arising from the left kidney. The diagnosis of benign retroperitoneal schwannoma was made by histologic examination and immunohistochemical staining of the excised mass. A practical algorithm for perinephric, retroperitoneal schwannomas is proposed.

Peripheral nerve schwannoma: two cases exhibiting increased FDG uptake in early and delayed PET imaging

We present two cases of peripheral nerve schwannoma which showed an increased accumulation of 2-deoxy-[(18)F] fluoro-D-glucose (FDG) in the tumors on positron emission tomography (PET) imaging acquired at both 1 h (early phase) and 2 h (delayed phase) after FDG injection. FDG-PET scans were performed with a dedicated PET scanner (HeadtomeV/ SET2400 W, Shimadzu, Kyoto, Japan) and the PET data analyzed the most metabolically active region of interest (ROI). We set the maximum standardized uptake value (SUV max) with a cut-off point of 3.0 to distinguish benign and malignant lesions. Although the mechanism responsible for the increased FDG uptake in benign schwannomas remains unknown, we discuss our findings in the context of tumor cellularity and briefly review other studies on the subject.

Retroperitoneal schwannoma bearing at the right vaginal wall

Benign schwannoma commonly arises from schwann cells of the neural sheath. We report a rare case of retroperitoneal schwannoma bearing at the vaginal wall. The tumor was a 7x5x4-cm solid mass revealed using several image techniques and diagnosed to be a retroperitoneal tumor preoperatively. The tumor was tightly attached to the vaginal submucosal tissue, so complete surgical resection was difficult. However, an almost complete resection was carried out macroscopically using laparotomy. Histologic and immunohistochemical studies confirmed the diagnosis. The patient has been followed for 18 months after the operation, but there is no evidence of recurrent tumor.

An unusual presentation of a rare nerve cell tumour

We present a rare case of a schwannoma in a pre/para-aortic position resembling a thrombosed saccular abdominal aortic aneurysm.