Retroperitoneal neural sheath tumors: Cleveland Clinic experience

Integrated Neurosurgical Management of Retroperitoneal Benign Nerve Sheath Tumors

Peripheral nerve sheath tumors (PNST) of the retroperitoneum are rare and are often treated by general surgeons dealing with retroperitoneal cancers. However, resection without the correct microsurgical technique can cause permanent neurological deficits and pain. Here, we discuss our interdisciplinary approach based on the integration of expertise from neurosurgery and abdominal surgery, allowing for both safe exposure and nerve-sparing microsurgical resection of these lesions. We present a series of 15 patients who underwent resection of benign retroperitoneal or pelvic PNST at our institution. The mean age of patients was 48.4 years; 67% were female. Tumors were 14 schwannomas and 1 neurofibroma. Eight patients (53%) reported neurologic symptoms preoperatively. The rate of complete resection was 87% (n = 13); all symptomatic patients showed improvement of their preoperative symptoms. There were no postoperative motor deficits; one patient (7%) developed a permanent sensory deficit. At a mean postoperative follow-up of 31 months, we observed no recurrences. To our best knowledge, this is the second-largest series of benign retroperitoneal PNST consistently managed with microsurgical techniques. Our experience confirms that interdisciplinary management allows for safe treatment of these tumors with good neurological and oncological outcomes.

A rare case of giant retroperitoneal neurilemmoma

Neurilemmoma, also known as schwannoma or neurinoma, is a tumor that originates from neural sheath Schwann cells. Giant neurilemmomas derived from the retroperitoneum have rarely been reported. We herein describe a woman with a giant retroperitoneal neurilemmoma that was initially incorrectly diagnosed as an inflammatory abdominal mass. The tumor extended from the patient's hypogastrium to her pelvic cavity and measured 20 × 15 × 10 cm. The tumor was excised via laparotomy and diagnosed as a retroperitoneal neurilemmoma through histological and immunohistochemical examination. Although rare, particularly in the giant form, neurilemmoma should be considered as an important differential diagnosis in patients with a retroperitoneal tumor or inflammatory abdominal mass. Complete excision should be considered for the potential cure of giant retroperitoneal neurilemmomas.

Clinical features and surgical treatment of sacral schwannomas

BACKGROUND

Sacral schwannoma is relatively rare and both the early diagnosis and appropriate treatment of sacral schwannomas are equally very challenging.

METHODS

11 sacral schwannoma cases operated at the Second Affiliated Hospital, School of Medicine, Zhejiang University, from 2012 to 2016, were investigated retrospectively and 10 were followed up. All patients were assessed with X-ray, CT and MRI, and underwent an intralesional excision.

RESULTS

One patient was male, nine were female and the average age was 48 (ranging between 31 and 63). Three patients suffered from back and leg pain, and seven had no obvious symptoms. The average blood loss during surgery was 980ml (ranging between 100 and 2,000ml). Six patients underwent preoperative biopsy. The surgeries were performed via the combination of an anterior and posterior approach in two patients, a posterior approach in seven patients, and an anterior approach in one patient. Residual tumors were not detected in all patients after surgery. Unfortunately, the postoperative complications occurred in three patients, namely bowel and bladder dysfunction (two patients) and cerebrospinal fluid leakage with secondary intracranial infection (one patient). The average follow-up was 22.7 months (8-44 months). All patients were relieved from preoperative symptoms after the last follow-up.

CONCLUSIONS

The typical findings of our cases in MRI were a well-circumscribed lesion with a heterogenous signal intensity on T2-weighted image, which may be helpful for preoperative decision-making. Intralesional excision can be successfully performed using single anterior or single posterior or both, and is an important procedure in the treatment of sacral schwannomas.

Unusual presentation of retroperitoneal leiomyosarcoma mimicking an adnexal tumor with highly elevated serum CA-19-9

When retroperitoneal leiomyosarcoma develops in pelvic cavity, it often presents similar symptoms and radiological findings to adnexal tumor, therefore obscures diagnostic approaches until an exploratory laparotomy is performed. We report an unusual presentation of retroperitoneal leiomyosarcoma mimicking an adnexal tumor with extremely elevated serum CA-19-9. Though the most of the prominent mass was removed during surgery, there was massive bleeding due to tearing of internal iliac vein while dissecting the ureter close to vessels. This case focuses on the significance of considering retroperitoneal tumor even if the mass is located in ovarian fossa and has highly elevated serum level of CA-19-9. And in attempt of tumor removal, the excision needs to be clean-cut without damaging nerves or vessels around the mass and avoid causing any prospective complications.

Sacrococcygeal neurofibroma: rare cause for chronic pelvic pain

Pelvic pain is a common gynecologic complaint. Retroperitoneal pelvic tumors are rarely a cause of pelvic pain. Neurofibroma is an uncommon pelvic retroperitoneal tumor, and only 17 cases are reported to date. A 38-year-old woman with chronic pelvic pain had a soft fixed mass that was the size of an orange in the right posterolateral fornix, with a normal uterus on pelvic examination, and a mass of 6.3 × 5.2 cm with mixed echotexture on the right side separate from both ovaries on transvaginal ultrasonography. A provisional diagnosis of retroperitoneal mass probably a retroperitoneal teratoma was made. Laparoscopy was performed; an ill-defined retroperitoneal soft tissue mass of about 6 cm was seen on the right pararectal and presacral area, displacing the rectum toward the left side. The mass was soft and jellylike without a cyst wall. Histopathologic study and immunohistochemistry results were consistent with neurofibroma of the sacrococcygeal regions. To our knowledge this is the third case of sacrococcygeal neurofibroma treated by complete laparoscopic excision. Gynecologists should keep sacrococcygeal neurofibroma as a differential diagnosis of pelvic pain with atypical location of a pelvic mass. A high index of suspicion and an appropriate imaging technique are needed for accurate diagnosis. Laparoscopy seems to be a safe and effective method of managing retroperitoneal presacral neurofibromas.

Laparoscopic management of obturator nerve schwannomas: experiences with 6 cases and review of the literature

OBJECTIVES

To present our experiences in management of obturator nerve schwannomas by laparoscopy.

PATIENTS AND METHODS

Six patients who were diagnosed preoperatively with pelvic tumors and histologically with obturator nerve schwannomas were treated by laparoscopy in our hospital between 1998 and 2009. Clinical data were obtained by a retrospective review of all the patients' medical records, radiologic reports, pathologic reports, and operation videos.

RESULTS

A total of 6 tumors were found in 6 patients, none of which was correctly, preoperatively diagnosed as a schwannoma. In 5 of them, obturator nerve roots were identified to be associated with the tumors during the operation. All of the tumors were resected successfully by laparoscopy, including 2 resected by enucleation. Postoperatively, 2 patients developed a permanent neurological deficit, 2 patients developed transient nerve neuropathy but complete resolution within 8 weeks, and the other 2 developed no neurological deficit. Pathologic examination showed that all the tumors were benign schwannoma. At a mean follow-up of 24 months (range, 12 to 48 mo) postresection, all the patients remained free from recurrence.

CONCLUSIONS

Pelvic schwannomas are rare and difficult to diagnose preoperatively. The intraoperative observation of the nerve running through the tumor may aid the diagnosis. Although obturator nerve injury does not seem to be associated with severe impairments, efforts should be made to preserve the integrity of the nerve. Laparoscopic surgery is a safe and feasible method for approaching benign schwannoma in the obturator fossa.

Retroperitoneal schwannoma

BACKGROUND

Retroperitoneal schwannomas are rare, benign tumors. The aim of this study is to present our surgical experience with 7 such tumors.

METHODS

Between 1989 and 2004, 7 patients with pathologically proven retroperitoneal schwannomas were reviewed retrospectively.

RESULTS

There were 6 male patients and 1 female patient, with a mean age of 43 years (range, 23 to 58 years). Two patients were symptomatic and presented with abdominal discomfort, and none of the patients suffered from von Recklinghausen's disease. All the patients underwent computed tomography scanning, which showed a heterogenous retroperitoneal mass, 4 of which were thought to arise from the adrenals. In 2 patients, calcification was seen in the tumors. All 7 of the patients had a preoperative diagnosis of a retroperitoneal tumor including 3 patients who were thought to have adrenal neoplasms (1 patient had a diagnosis of an adrenal neoplasm excluded on magnetic resonance imaging). Laparotomy and complete excision of tumors were performed in all the patients, and there was no morbidity or mortality. The schwannomas had a mean maximum diameter of 7.3 cm (range, 4 to 14 cm), and they were all benign. At a mean follow-up of 17 months (range, 3 to 48 months) postresection, all the patients remained free from recurrence.

CONCLUSION

Retroperitoneal schwannomas are rare tumors that are difficult to diagnose preoperatively. Radiologic findings are usually nondiagnostic. The treatment of choice is complete surgical excision.

[Malignant retroperitoneal schwannoma]

We present an uncommon case of retroperitoneal malignant schwannoma diagnosed accidentally. The clinical, diagnostic and therapeutic features are discussed.

Benign retroperitoneal schwannoma: a case series and review of the literature

OBJECTIVES

To present our experience with four retroperitoneal schwannomas treated by surgical excision and review the current literature. Retroperitoneal schwannomas are rare, benign tumors and infrequently present to the urologist.

METHODS

From 1997 through 2002, the charts of 164 patients with a diagnosis of benign retroperitoneal soft tissue mass were reviewed. Of those, four had a pathologic diagnosis of retroperitoneal schwannoma.

RESULTS

Three of the 4 patients were women, with a median age of 54 years (range 46 to 80). The average tumor size was 13.7 cm (range 8.8 to 20). All patients underwent magnetic resonance imaging, computed tomography, or ultrasonography, and 3 of the 4 patients underwent a computed tomography-guided fine needle aspiration biopsy (all were either inaccurate or inconclusive). All patients underwent complete tumor excision with free margins of resection and tolerated surgery without any complications. None of the patients have had any evidence of recurrence at a mean follow-up of 26 months (range 10 to 48).

CONCLUSIONS

Retroperitoneal schwannomas are difficult to diagnose preoperatively. Computed tomography-guided fine needle aspiration biopsy does not appear to provide an accurate preoperative diagnosis. The surgical approach should focus on complete excision of the mass. Patients undergoing complete surgical resection tend to do well without evidence of early recurrence.

Nerve sheath tumors involving the sacrum. Case report and classification scheme

Nerve sheath tumors that involve the sacrum are rare. Delayed presentation is common because of their slow-growing nature, the permissive surrounding anatomical environment, and nonspecific symptoms. Consequently, these tumors are usually of considerable size at the time of diagnosis. The authors discuss a case of a sacral nerve sheath tumor. They also propose a classification scheme for these tumors based on their location with respect to the sacrum into three types (Types I-III). Type I tumors are confined to the sacrum; Type II originate within the sacrum but then locally metastasize through the anterior and posterior sacral walls into the presacral and subcutaneous spaces, respectively; and Type III are located primarily in the presacral/retroperitoneal area. The overwhelming majority of sacral nerve sheath tumors are schwannomas. Neurofibromas and malignant nerve sheath tumors are exceedingly rare. Regardless of their histological features, the goal of treatment is complete excision. Adjuvant radiotherapy may be used in patients in whom resection was subtotal. Approaches to the sacrum can generally be classified as anterior or posterior. Type I tumors may be resected via a posterior approach alone, Type III may require an anterior approach, and Type II tumors usually require combined anterior-posterior surgery.

Chronic sciatica secondary to retroperitoneal pelvic schwannoma

Pelvic schwannoma is a rare cause of sciatic pain. We report a case of retroperitoneal pelvic schwannoma presenting with chronic sciatica which was diagnosed and monitored radiologically for several years before successful surgical resection.

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

The occurrence of massive retroperitoneal schwannomas is extremely rare and their presence may only be expressed by insidious onset of non-specific and misleading symptoms with a predominance of lower back pain. MRI scan as the imaging procedure of choice will demonstrate the tumour location and its relation to the surrounding structures, but due to heterogeneity and degeneration in some tumours, it may mimic malignancy. Hence tissue sampling through needle biopsies are essential to verify the diagnosis prior to surgery. Tumour excision in toto is considered the treatment of choice, but it can be hazardous especially if the tumour is adherent to the presacral venous plexus. Severe bleeding complications due to the damage of venous structures have to be encountered, and establishing lasting haemostasis may pose considerable difficulties. Hence surgery should be attempted with full precautions, and preoperative counseling of the patient. If malignancy can safely be excluded, laparoscopic piecemeal excision should be considered as an alternative treatment as recurrence is unlikely. Definition of the originating nerve might not always be possible and a minor degree of neurological impairment has therefore to be anticipated.

Presacral solitary giant neurofibroma without neurofibromatosis type 1 presenting as pelvic mass--case report

A 35-year-old woman presented with a solitary neurofibroma in an unusual presacral location without neurofibromatosis manifesting as bilateral chronic sciatica for 2 years. She was initially considered as having a giant right ovarian mass, but was referred with a prediagnosis of solitary giant sacral nerve sheath tumor. The initial differential diagnosis was based on neuroimaging. A right-sided J incision with the extraperitoneal approach provided good exposure and handling of the tumor bed. Almost total excision without neurological deficit was possible. The histological diagnosis was neurofibroma. Benign retroperitoneal neural sheath tumors in patients without von Recklinghausen's disease are quite rare. Intrapelvic tumors are often diagnosed at a later stage. Neuroimaging is very helpful to delineate this unusual site and the extent of tumor development, and to determine the appropriate surgical intervention. A clear understanding of retroperitoneal anatomy is essential for safe removal of such tumors. Complete resection is preferred to prevent local recurrence and malignant transformation. Although root section is inevitable, neurological deficit is unlikely.

Presacral schwannoma with purely cystic form

STUDY DESIGN

Case report.

OBJECTIVE

To point out that presacral schwannoma can display markedly cystic degeneration.

SUMMARY OF BACKGROUND DATA

Benign schwannoma sometimes displays degenerative changes, such as cyst formation, calcification, hemorrhage, and hyalinization. Usually these degenerations are partially seen in the tumors.

METHODS

Medical history, physical findings, imaging features, and histologic findings were reviewed in a case with a large presacral schwannoma.

RESULTS

A 62-year-old woman presented with an 18-month history of right sciatic pain. Magnetic resonance images detected a large cystic, presacral tumor. Initially the tumor was misdiagnosed as a cystic ovarian tumor. Preoperative diagnostic workup led to the diagnosis of cystic schwannoma. Intralesional curettage achieved good pain relief.

CONCLUSIONS

This tumor was unusual in its totally cystic appearance and resemblance to a cystic ovarian tumor or anterior sacral meningocele. Preoperative diagnosis is important to prevent major neurologic deficit at surgery.

[Retroperitoneal benign schwannoma. Report of a new case]

The schwannoma is a tumor resulting from the Schwann cells of neural shwath, being its retroperitoneal localization quite unusual. This tumor is clinically unspecified and in most of the cases it originates symptoms coming from the compression of the close structures when its localization is retroperitoneal. Its diagnosis is quite often fortuitous being confirmed by anatomopathological study afterwards. The treatment is surgical radical exeresis with subsequent followup. We report a new case of this uncommon retroperitoneal pathology in a female patient showing a nonspecific clinic. Two years after the surgery she remains asymptomatic without any radiological evidence of recidive.

Schwannoma of the urinary bladder: a case report

The urinary bladder is an extremely rare site for primary schwannomas. They are most often associated with von Recklinghausen disease. This patient was found to have a schwannoma of the bladder in the absence of evidence of von Recklinghausen disease and was successfully treated with a partial cystectomy. This represents only the third such case in the literature of this entity.

CT features of retroperitoneal neurilemmoma

PURPOSE

The aim of this study was to characterize the CT features of retroperitoneal neurilemmoma.

METHODS

The CT findings were reviewed in seven patients with retroperitoneal neurilemmoma.

RESULTS

All of the tumours were well-demarcated round or oval masses. In five cases, heterogeneous contrast enhancement was noted after contrast medium administration. Areas of minimal enhancement reflected diffuse edema in one tumour. Areas without definite enhancement represented prominent cyst formation in three tumours. There were three cases with tumour calcification (two with punctate calcification and one with mottled calcification).

CONCLUSION

CT findings may suggest the diagnosis of retroperitoneal neurilemmoma preoperatively.

Differential diagnosis of primary benign and malignant retroperitoneal tumors

BACKGROUND

Clinical differential diagnosis between malignant and benign tumors is important in order to select a therapeutic strategy for a primary retroperitoneal tumor.

METHODS

The clinical findings and radiological features of 25 patients with primary retroperitoneal tumors were retrospectively evaluated to find those signs that might contribute to the preoperative distinction between benign and malignant tumors.

RESULTS

Of 25 primary retroperitoneal tumors, 15 were benign. This may reflect the increased number of incidentally found small benign tumors. There were significant associations between the presence of symptoms and malignancy (P < 0.05), between irregular margins on imaging and malignancy (P < 0.05) and between the absence of calcification and malignancy (P < 0.05). Malignant tumors were significantly larger than benign tumors (11.45 +/- 1.90 cm vs. 5.31 +/- 0.43 cm). A retroperitoneal tumor scoring system was developed to distinguish primary retroperitoneal benign tumors from their malignant counterparts based on the: 1) maximum diameter equal to or larger than 5.5 cm, 2) presence of symptoms, 3) absence of calcification, 4) presence of irregular margins, and 5) presence of cystic degeneration or necrosis. A significant correlation was found between the incidence of malignant tumors and the total retroperitoneal tumor score (P < 0.05).

CONCLUSION

This study suggests that the size of tumor, the presence of symptoms, irregular margins, and the absence of calcification may be valuable predictors of primary retroperitoneal malignant tumor.

Benign retroperitoneal neural sheath tumors in patients without von Recklinghausen's disease

Benign retroperitoneal neural sheath tumors in patients without von Recklinghausen's disease are quite rare and usually presented as isolated case reports. There are two types of benign neural sheath neoplasms: schwannoma and neurofibroma. Confusion exists in the nomenclature of these tumors due to the disagreement upon their cell of origin. In a collective report from two institutions, three cases with benign retroperitoneal neural sheath tumors are presented, and the histological features, diagnostic and therapeutic options are discussed.

MR imaging differentiation of benign and malignant peripheral nerve sheath tumors: use of the target sign

BACKGROUND

T2-weighted MR imaging of soft tissue tumors of neural origin may show round lesions with a central hypointensity and a hyperintense rim resembling a target. We define the "target sign" as a mass consisting of a solitary target, or a multicompartmental mass in which the largest component consists of multiple targets.

OBJECTIVE

The objective of this study was to determine whether the target sign can differentiate benign neurofibromas and their malignant counterparts, malignant peripheral nerve sheath tumors. Materials and methods. Preoperative T2-weighted MR images of 23 neurofibromas or malignant peripheral nerve sheath tumors were retrospectively reviewed in 16 patients, aged 3 weeks to 20 years (median 15 years), without knowledge of the pathologic diagnosis. The presence or absence of a target sign was noted.

RESULTS

The target sign was seen in all 12 neurofibromas and 1 of the 11 malignant peripheral nerve sheath tumors. Statistical analysis showed good differentiation of benign and malignant tumors using this sign (chi = 0.91).

CONCLUSION

The target sign on T2-weighted MR imaging is helpful in differentiating neurofibromas from malignant peripheral nerve sheath tumors.

Primary diaphragmatic schwannoma with a typical target appearance: correlation of CT and MR imagings and histologic findings

A rare case of benign diaphragmatic schwannoma in a 38-year-old female is reported. Precontrast computed tomography (CT) showed an encapsulated well-defined round homogeneous tumor with central calcification, measuring approximately 5 cm in diameter, arising from the left diaphragm. Contrast-enhanced CT and gadolinium-enhanced T1-weighted magnetic resonance (MR) imaging showed focal enhancement in the central portion of the tumor. The tumor showed a typical target appearance of increased peripheral signal intensity and decreased central signal intensity on unenhanced T2-weighted images. Pathological examination of resected specimens of the tumor showed two zonal histological components: a hypercellular portion of spindle cells with nuclear palisading (Antoni A tissue) and a hypocellular portion of cells with cystic degeneration, together with focal calcification and hemangeomatous vascular changes (Antoni B tissue). We consider the radiological characteristics of diaphragmatic schwannoma on CT and MR imagings to represent the geographic difference between the histologic zones of the tumor.

MR imaging in the diagnosis of a retroperitoneal schwannoma

The computerized tomography (CT) and ultrasound characteristics of many of the primary retroperitoneal tumors are nonspecific, and thus preoperative diagnosis of these tumors is difficult. We describe a case of a retroperitoneal schwannoma in which the multiplanar capability of magnetic resonance imaging (MRI) provided anatomic information not obtainable by other modalities and helped to suggest the neural origin of the tumor.

Multiple retroperitoneal schwannomas: case report and review of the literature

We report a rare case of multiple retroperitoneal schwannomas, initially believed to be an adrenal carcinoma with metastasis. These benign tumors were discovered in a patient presenting with vague back pain. Preoperative radiographic and endocrine evaluations suggested a nonfunctioning adrenal tumor. The final diagnosis and its juxta-adrenal origin were confirmed by histological and immunohistochemical studies. A review of the literature on retroperitoneal schwannoma is included.

Benign schwannoma of the retroperitoneal space: case report

We report a case of retroperitoneal benign schwannoma involving the left femoral and obturator nerves. The difficulties of diagnosis are discussed and the potential complications of tumor removal are described.

Giant pre-sacral neurofibroma

We report a case of pre-sacral neurofibroma diagnosed on a routine medical examination. The pathological features and management criteria of these rare tumours are discussed.