Imaging features of retroperitoneal and pelvic schwannomas

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.

Imaging in gynecological disease (26): clinical and ultrasound characteristics of benign retroperitoneal pelvic peripheral-nerve-sheath tumors

OBJECTIVE

To describe the clinical and sonographic characteristics of benign, retroperitoneal, pelvic peripheral-nerve-sheath tumors (PNSTs).

METHODS

This was a retrospective study of patients with a benign, retroperitoneal, pelvic PNST who had undergone preoperative ultrasound examination at a single gynecologic oncology center between 1 January 2018 and 31 August 2022. All ultrasound images, videoclips and final histological specimens of benign PNSTs were reviewed side-by-side in order to: describe the ultrasound appearance of the tumors, using the terminology of the International Ovarian Tumor Analysis (IOTA), Morphological Uterus Sonographic Assessment (MUSA) and Vulvar International Tumor Analysis (VITA) groups, following a predefined ultrasound assessment form; describe their origin in relation to nerves and pelvic anatomy; and assess the association between their ultrasound features and histotopography. A review of the literature reporting benign, retroperitoneal, pelvic PNSTs with preoperative ultrasound examination was performed.

RESULTS

Five women (mean age, 53 years) with a benign, retroperitoneal, pelvic PNST were identified, four with a schwannoma and one with a neurofibroma, of which all were sporadic and solitary. All patients had good-quality ultrasound images and videoclips and final biopsy of surgically excised tumors, except one patient managed conservatively who had only a core needle biopsy. In all cases, the findings were incidental. The five PNSTs ranged in maximum diameter from 31 to 50 mm. All five PNSTs were solid, moderately vascular tumors, with non-uniform echogenicity, well-circumscribed by hyperechogenic epineurium and with no acoustic shadowing. Most of the masses were round (n = 4 (80%)), and contained small, irregular, anechoic, cystic areas (n = 3 (60%)) and hyperechogenic foci (n = 5 (100%)). In the woman with a schwannoma in whom surgery was not performed, follow-up over a 3-year period showed minimal growth (1.5 mm/year) of the mass. We also summarize the findings of 47 cases of benign retroperitoneal schwannoma and neurofibroma identified in a literature search.

CONCLUSIONS

On ultrasound examination, no imaging characteristics differentiate reliably between benign schwannomas and neurofibromas. Moreover, benign PNSTs show some similar features to malignant retroperitoneal tumors. They are solid lesions with intralesional blood vessels and show degenerative changes such as cystic areas and hyperechogenic foci. Therefore, ultrasound-guided biopsy may play a pivotal role in their diagnosis. If confirmed to be benign PNSTs, these tumors can be managed conservatively, with ultrasound surveillance. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Extraprostatic incidental findings on prostate mpMRI: A pictorial review from the ESUR junior network

The role of multiparametric MRI (mpMRI) in prostate cancer setting is increasingly consolidated and, as a result, its usage in clinical practice is in exponential growth. However, beyond the prostate gland, several key structures are included in the field of view of mpMRI scans. Consequently, various extra-prostatic incidental findings (IFs) belonging to different anatomical systems can be accidentally recognized. Therefore, it is mandatory for a radiologist to be familiar with the wide range of pathologies potentially encountered, to guide management and avoid patient anxiety and costs due to additional work-up prompted by clinically insignificant extra-prostatic findings. With this pictorial review, we aim to illustrate a wide range of IFs that can be detected when performing mpMRI of the prostate, focusing on their imaging characteristics, differential diagnosis, and clinical relevance. Additionally, we propose the CheckDEEP, the Checklist for DEtection of ExtraProstatic findings, to be used for a thorough evaluation of target areas within each anatomical system.

Beyond squamous cell carcinoma: MRI appearance of uncommon anal neoplasms and mimickers

Anal cancer is an uncommon malignancy. In addition to squamous cell carcinoma, there are a variety of other less common malignancies and benign pathologies that may afflict the anal canal, with which abdominal radiologists should be familiar. Abdominal radiologists should be familiar with the imaging features that can help distinguish different rare anal tumors beyond squamous cell carcinoma and that can aid in diagnosis therefore help steer management. This review discusses these uncommon pathologies with a focus on their imaging appearance, management, and prognosis.

Cystic lesions of the retrorectal space

Cysts of the retrorectal space comprise a heterogeneous group of rare lesions. Most develop from embryological remnants and include tailgut cysts, dermoid cysts, rectal duplication cysts, anal canal duplication cysts, sacrococcygeal teratomas and anterior meningocoele. Tailgut cyst is the most common cyst of developmental origin, usually presenting as a multilocular cystic mass with mucoid content and lined by multiple epithelial types. Compared with tailgut cysts, rectal duplication cysts display all layers of the large bowel wall including a well-defined muscularis propria. Retrorectal cysts of non-developmental origin are far less common and represent lesions that either infrequently involve the retrorectal space or undergo extensive cystic change. This review provides an overview of the various histological types of cystic lesions of the retrorectal space, divided into cysts of developmental origin and those of non-developmental origin. A practical pathological and multidisciplinary approach to diagnosing these lesions is presented.

Clinical presentation, management, and research progress of adrenal schwannoma

Objective

This study shares our experience in managing adrenal schwannoma (AS).

Methods

The clinical data of eight patients with AS in our hospital from April 2007 to April 2022 were analyzed retrospectively.

Results

A total of 1309 patients with adrenal lesions were treated in the affiliated hospital of Guizhou Medical University for 15 years, of which only 8 cases were diagnosed as AS, accounting for 0.61%. Among the eight patients with AS, there were five females and three males, with an average age of 48.63 ± 12.05 years, and the average maximum diameter of the tumor was 6.96 ± 1.83 cm. All patients underwent adrenalectomy and were pathologically diagnosed as AS after the operation. The average follow-up time of eight patients with AS was 60.13 ± 22.33 months, and there was no recurrence or metastasis.

Conclusion

The retroperitoneum is an uncommon site for schwannoma tumors, and among adrenal incidentalomas, the schwannoma is rare. The disease lacks specific clinical and imaging features, but correct diagnosis before the pathological examination is very important for clinical management and surgical decision. When imaging examination indicates a slow-growing retroperitoneal mass, schwannoma should be considered. Surgical resection is the main treatment. Pathology is the gold standard for diagnosis. Most of the tumors are benign and have a good prognosis. There is a risk of recurrence after the operation, and it should be monitored actively.

Surgical management of ancient retroperitoneal schwannoma

Schwannomas are benign and rare entities of peripheral nerve sheath origin. The clinical presentation depends the size of tumor, and they may cause symptoms of abdominal pain, urinary difficulties, anemia, hematuria, and abdominal mass as a result of the pressure of the tumor to the adjacent structures. The diagnosis can only be established by immunohistochemical study. Complete surgical clearance remains the mainstay of treatment.

We report the case of a 35-year-old female patient consulted for chronic abdominal pain. Abdominal ultrasound and abdomino-pelvic CT scan identified a well-delineated, heterogenous retroperitoneal mass developed in anteraortocaval region measuring 55 × 65 × 88 mm. The lesion seemed to repress the inferior vena cava, and enhanced with contrast administration. The histopathological panel confirmed the diagnosis of retroperitoneal schwannoma.

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Schwannomas are benign and rare entities of peripheral nerve sheath origin.

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They do not lead to an invasion of the adjacent structures; however the compression and displacement of the retroperitoneal organs are marked as complications of increasing in size of these entities.

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The total excision is the sole treatment for retroperitoneal schwannoma.

Rare case of pelvic schwannoma mimicking intra-ligamenter uterine fibroid: A case report

INTRODUCTION AND IMPORTANCE

Schwannomas are benign tumors originating from Schwann cells of nerve fibers. Pelvic schwannomas are extremely rare. Here, we present a case of a 48-year-old woman with a pelvic schwannoma imitating degenerating cystic leiomyoma.

CASE PRESENTATION

A 48-year-old woman presented with brown-yellowish bloody vaginal discharge, fever, abdominal enlargement, and pain. Abdominal ultrasound showed a homogeneous solid mass with a clear border separated from the uterus and left ovary. Computed tomography (CT) scan revealed a multilocular cystic mass with thick septa and solid enhancing component. Histopathological examination showed a mesenchymal tumor composed of cells with fine chromatin. The nuclei were oval or round, and some cells exhibited spindle and cigar-shaped nuclei. Tumor cells had an abundant amount of eosinophilic cytoplasm. Immunohistochemical examination demonstrated positive expression for S100 as specific staining for schwannomas. Mitosis was not found, and hyalinized blood vessels were observed.

CLINICAL DISCUSSION

Compression by the tumor into the surrounding organs, such as the bladder and intestines, could cause difficulty with defecation and urination in patients. The absence of specific signs and symptoms can lead to a misdiagnosis of pelvic schwannoma. Surgery is the treatment of choice. It is difficult to establish a definitive diagnosis before surgery. Laparotomy approach was taken and a histopathological examination was completed to confirm the diagnosis.

CONCLUSION

Unspecified pelvic pain with abdominal mass may suggest a rare tumor such as schwannoma. Transvaginal ultrasonography is incapable of reliably distinguishing between schwannoma and other tumors.

Pelvic schwannoma in an adult male

Schwannomas are benign nerve sheath tumors that are generally encapsulated and commonly detected in the head, neck, and mediastinal regions. Schwannomas localizing in the pelvis are extremely rare and tend to be asymptomatic initially due to slow growth rate. Schwannomas may be misdiagnosed as urologic or gynecologic tumors. Pelvic schwannomas are typically solitary, large, and well-circumscribed masses in the retroperitoneum or presacral areas. Other imaging characteristics are cystic degeneration, repeated hemorrhages, and calcifications. Calcification patterns can be punctate, speckled, curvilinear, or along the walls of the masses. We report a young man with a pelvic schwannoma with typical imaging features.

Tumor retrorrectal: Reporte de un caso de Schwannoma

Introducción. En el espacio retrorrectal o presacro pueden desarrollarse lesiones tumorales, tanto benignas como malignas. La mayoría de los pacientes son asintomáticos y, cuando presentan síntomas, éstos son inespecíficos. Entre los tumores retrorrectales se destaca el grupo de origen neurogénico, donde el Schwannoma es el más frecuente. Caso clínico. Mujer de 32 años, con tumor retrorrectal, que producía una sintomatología escasa e imprecisa, diagnosticado durante una intervención quirúrgica por mioma uterino, que finalmente resultó ser un Schawnnoma. Conclusión. La tomografía computarizada y la resonancia magnética son importantes para el diagnóstico y para establecer el nivel de la lesión en relación con el sacro. La piedra angular del tratamiento es la resección quirúrgica. El abordaje puede ser anterior (abdominal), posterior (perineal, transsacro o parasacrococígeo) o combinado, de acuerdo con su localización al nivel S4.

A Case of Incidental Schwannoma Mimicking Necrotic Metastatic Lymph Node from Bladder Cancer

Background and Objectives: Retroperitoneal schwannoma is a very rare case of schwannoma which commonly occurs in the other part of the body. However, it is difficult to distinguish schwannoma from other tumors before pathological examination because they do not show specific characteristics on imaging study such as ultrasound, computed tomography (CT), and magnetic resonance image (MRI). Case summary: A 60-year-old male showed a retroperitoneal cystic tumor which is found incidentally during evaluation of coexisted bladder tumor. Neurogenic tumor was suspicious for the retroperitoneal tumor through pre-operative imaging study. Finally, a schwannoma was diagnosed by immunohistochemical examination after complete surgical excision laparoscopically. Conclusion: As imaging technology is developed, there may be more chances to differentiate schwannoma from other neoplasm. However, still surgical resection and histopathological examination is feasible for diagnosis of schwannoma.

Diagnostic approach to primary retroperitoneal pathologies: what the radiologist needs to know

Retroperitoneal soft tissue lesions represent a wide range of disease processes with overlapping imaging findings. Familiarity with the CT and MR characteristics of these conditions is important to guide clinical evaluation. We review the tissue types, characteristic clinical, demographic, and imaging features of retroperitoneal tumors and tumor-like non-neoplastic conditions with CT and MR correlation, including anatomic and imaging clues, and provide a diagnostic approach to aide the radiologist in making a specific diagnosis.

Retroperitoneal Schwannoma: Two Rare Case Reports

Schwannomas are neuroectodermal tumors that rarely occur in the retroperitoneal space. We report two cases of patients who presented with abdominal pain. Radiological findings revealed a retroperitoneal mass in both cases. Both patients underwent complete surgical excision with an uneventful postoperative course. The histopathological study confirmed the nature of schwannoma. Complete surgical excision remains the gold standard for the management of these tumors. The preoperative diagnosis is usually difficult; however, the definitive diagnosis is made upon histopathological examination.

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.

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.

Retroperitoneal tumors: Review of diagnosis and management

Retroperitoneal tumors are extremely rare tumors occurring in the retroperitoneum. Retroperitoneal tumors are divided into benign tumors and malignant tumors, including retroperitoneal sarcoma. Approximately 70-80% of primary retroperitoneal soft-tissue tumors are malignant; however, these only account for 0.1-0.2% of all malignancies. Retroperitoneal sarcoma is an orphan malignant disease with a low incidence. The information on benign retroperitoneal tumors is limited. The American Joint Committee on Cancer/TNM classification updated to the 8th edition in 2017. In 2010, three new drugs for soft tissue sarcoma were approved based on the results of phase III trials, but the histological subtypes of the patients enrolled in the trials of each drug differed. Recently, in addition to surgery for retroperitoneal sarcoma, the effectiveness of perioperative radiation therapy has become interesting. For malignant retroperitoneal tumors and retroperitoneal sarcoma, survival improvement and locoregional recurrence prevention can be undertaken by carrying out surgery to secure negative margins with wide and combined resection of some adjacent organs, and cooperation with a trained medical team comprising of radiologists, pathologists and medical oncologists in centralized hospitals. Some clinical trials aimed at further improving treatment results by adding preoperative chemotherapy and radiation therapy based on histological confirmation using a correct needle biopsy are in progress. In recent years, molecular profiling has been used to select eligible patients for chemotherapy. In the future, precision medicine with next-generation sequencing technology will be expected among the diverse and potential future treatments for retroperitoneal sarcoma. In this review, we summarized the current state of retroperitoneal tumors and retroperitoneal sarcoma.

Adrenal schwannoma: a case report

Retroperitoneum is an uncommon site for Schwannoma tumors and among adrenal incidentaloma the Schwannoma is rare. This condition lacks of a specific clinical and radiological features, but correct diagnosis before pathological examination should be very important for clinical management and surgical decision. We describe a case of voluminous retroperitoneal incidental mass, that was proved to be an adrenal Schwannoma.

Natural Progression and Factors Predicting Growth of Retroperitoneal Schwannoma

BACKGROUND

Although knowledge of the natural history of retroperitoneal schwannoma, including growth rate, would be useful when determining the indications and timing of surgical treatment for such nonpalpable tumors, the existing evidence is unclear. We examined the natural history of retroperitoneal schwannoma and assessed whether magnetic resonance imaging (MRI) and clinical findings predict future growth.

METHODS

Among patients with retroperitoneal schwannoma treated in our department during the period from January 1, 2015 through December 31, 2015, eight who underwent follow-up assessment by MRI and did not undergo tumor resection for longer than 1 year were enrolled. Changes in lesion size were examined in relation to selected clinical and MRI findings. In cases of pressure erosion in the vertebral body, change in the size of the intraosseous region was compared to change in the size of the whole lesion.

RESULTS

Median absolute growth rate (AGR) was 1.9 cm³ per year, median relative growth rate (RGR) was 5.6% per year, and median tumor volume doubling time (VDT) was 3.1 years. AGR, RGR, and VDT were not associated with any clinical variable. RGR and VDT values in the intraosseous region were about twice those of the whole lesions.

CONCLUSIONS

The growth rates of retroperitoneal schwannomas varied. Additionally, no MRI or clinical findings predicted growth of retroperitoneal schwannoma. Therefore, careful follow-up is necessary for this tumor type, especially for lesions with bone erosion.

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.

Two Unusual Presentations of Presacral Schwannoma; A Case Series

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Schwannomas are benign tumors that commonly occur in the head and neck, mediastinum and extremities.

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Pelvic schwannomas are very rare.

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Patients with pelvic schwannomas have different clinical presentations.

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We reported 2 cases of schwannomas found at the presacral area.

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The mass was found incidentally in one of the cases and the patient was completely asymptomatic.

Introduction

Schwannomas are benign tumors that arise from the Schwann cells of nerve fibers. They commonly occur in the head and neck, mediastinum and extremities. However, they are extremely rare to be found in the pelvis.

Case presentation

We report two cases of pelvic presacral schwannomas found in our hospital. The first case is a 50 years old lady who was seen in the outpatient clinic complaining of pelvic heaviness. Investigations were done including Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) which showed a solid mass in the presacral area. Biopsy was taken, and results came back as schwannoma. The patient underwent exploratory laparotomy and total tumor resection. The second case is a 19 years old gentleman who was referred from a local hospital to our hospital for further evaluation of an asymptomatic left retroperitoneal pelvic mass. The mass was found incidentally after a Road Traffic Accident. The patient underwent exploratory laparotomy and total tumor resection. In the two cases, specimen histopathology report came back positive for schwannoma and patients were doing fine in the post-operative period with no signs of recurrence till this date.

Conclusion

Due to the few cases in the literature, the diagnosis of presacral schwannoma is challenging. Some patients presented with vague symptoms like pelvic heaviness as seen with the patient in the first case, and some presented completely asymptomatic as seen with the patient in the second case. In symptomatic and asymptomatic cases, surgical excision is the mainstay of treatment of these tumors.

The natural history of incidental retroperitoneal schwannomas

The natural history of asymptomatic retroperitoneal schwannomas is poorly understood. This study aimed at investigating the natural history of incidental retroperitoneal schwannomas. The medical charts and imaging studies of 22 asymptomatic patients under observation for at least 12 months for retroperitoneal schwannomas were reviewed. The duration of follow-up ranged between 13 and 176 months (mean 48 months). In the 22 patients managed by the “wait and see” approach, the average tumor size at initial presentation was 51 mm, which increased to 57 mm at final follow-up. During the final follow-up, 2 patients required surgical treatment for tumor enlargement, while the remaining patients remained asymptomatic without surgery. The average growth rate of the tumors was 1.9 mm/year (range: -1.9 to 8.7 mm/year). The majority of asymptomatic retroperitoneal schwannomas demonstrate minimal growth and may be suitable for management with the “wait and see” approach.

Sonographic appearances of adrenal schwannomas

OBJECTIVE

To evaluate the sonographic ultrasound (US) appearances of adrenal gland schwannomas.

MATERIALS AND METHODS

This was a retrospective analysis of 15 cases of schwannomas involving the adrenal gland. The following US features were assessed: size, border, echogenicity, homogeneity, intralesional cystic necrosis, presence of septa, intralesional calcification, posterior acoustic enhancement and blood supply.

RESULTS

Of the 15 tumors, seven (46.7%) were located on the left side, and the remaining eight (53.3%) on the right side. The most frequent US appearance of adrenal schwannoma was a single, well-defined and isoechoic mass. The internal echotexture was homogeneous in 2 cases, and heterogeneous in 13 cases, with intralesional cystic areas (n = 11), septa (n = 10) or calcifications (n = 6). Posterior acoustic enhancement was seen in 12 of the 15 cases (80%). On color Doppler US, 86.7% (13/15) of the lesions did not show any vascularity.

CONCLUSIONS

Adrenal schwannomas usually present on US as well-defined isoechoic masses often with posterior acoustic enhancement, cystic necrosis with septa and poor blood supply. These appearances should suggest the diagnosis of adrenal schwannomas. Nevertheless, additional information from laboratory tests and CT or MR imaging may be required to avoid unnecessary surgery.

Practical approach to primary retroperitoneal masses in adults

Primary retroperitoneal masses constitute a heterogeneous group of uncommon lesions and represent a challenge due to overlapping imaging findings. Most are malignant lesions. Although they are more prevalent in adults, they can occur at any age. Such lesions are classified as primary when they do not originate from a specific retroperitoneal organ and are divided, according to the image findings, into two major groups: solid and cystic. The clinical findings are nonspecific and vary depending on the location of the lesion in relation to adjacent structures, as well as on its behavior. The main imaging methods used for staging and surgical planning, as well as for selecting the biopsy site and guiding the biopsy procedure, are computed tomography and magnetic resonance imaging. In most cases, the treatment is challenging, because of the size of the lesions, vascular involvement, or involvement of adjacent organs. In this article, we present a review of the retroperitoneal anatomy and a practical approach to the main imaging features to be evaluated, with a view to the differential diagnosis, which can guide the clinical management.

Perineal schwannoma: an unusual tumor and clinical presentation – first case with erectile dysfunction associated with this neoplasm

Introduction:

Perineal schwannomas (PS) are very rare benign tumors with few cases reported in literature and none of these reports erectile dysfunction among clinical presentations.

Case description:

We report a case of PS with unusual clinical presentation showing erectile dysfunction associated with perineal pain and discomfort during defecation, and the postoperative residual pain and erectile dysfunction treatment.

Conclusions:

On the basis of a literature review of all cases reported and on our case reported, we have delineated a clinical, diagnostic, and therapeutic profile of PS, summarized in a useful table.

Retroperitoneal Knee Pain: An Unusual Case Report and Review of an Ancient Schwannoma

Schwannomas are nerve sheath tumors that occur in Schwann cells. They are usually benign, but malignant transformation can occur. Symptomatology depends on the involvement of the surrounding tissues or the mass effect of the tumor. We describe a case of a 28-year-old man who initially presented with right iliac fossa pain associated with radiating pain over the anterior and lateral aspect of his right knee. Following subsequent investigations, we found a retroperitoneal schwannoma of the right lateral femoral cutaneous nerve. The key to our diagnosis was the referred pain to his right knee, which gave us a clue of possible neuropathic pain. Our patient highlights the need to consider a unified diagnosis when faced with an incongruent set of symptoms. Magnetic resonance imaging is the diagnostic modality of choice for the diagnosis of schwannomas. Treatment is directed towards symptomatic control. Surgery, radiation, and, in rare instances, chemotherapy are the major treatment modalities employed.

Retroperitoneal Schwannomas: Diagnostic and Therapeutic Implications

Aims and background

Schwannomas are a rare group of soft-tissue tumors that are derived from the peripheral nerve sheath and rarely develop in the retroperitoneum.

Methods and study design

We reviewed the clinicopathological features of 4 patients referred to our unit between October 1999 and March 2004 who on radiological examination were diagnosed with pancreatic, adrenal, psoas and retroperitoneal fat tissue tumors and subsequently underwent surgical treatment.

Results

The preoperative diagnosis was incorrect in all cases. At time of surgery, we found a mass probably arising from the adrenal gland in 2 patients, a lesion originating from the femoral nerve in 1 patient, and a retroperitoneal mass without a clear site of origin in 1 patient. Pathological evaluation revealed schwannomas in all cases, with no signs of malignancy. Complete surgical excision was performed in all patients without any major postoperative complications. At the time of writing all patients are alive with no evidence of local or distant recurrence.

Conclusions

Radical surgical excision is considered the best treatment for these neoplasms, resulting in a very good long-term prognosis.

Single Stage Posterior Approach for Total Resection of Presacral Giant Schwannoma: A Technical Case Report

The neurogenic tumor of frequent occurrence in the presacral area is a schwannoma. Giant presacral schwannoma has a risk for anterior surgical approach because of its massive size and proximity to abundant vascularity of presacral region. We report a single stage posterior approach for total resection of a giant presacral schwannoma. A 40-year-old female patient experienced left buttock pain and tingling sensation at left S1 dermatome. Magnetic resonance imaging showed that the presacral huge mass at S1–3 level with osseous extension and structural remodeling in left sacral ala. The presacral mass was ranging in maximum diameter from 8.0 to 8.6 cm. S2 foramen laminectomy was performed to expose the mass. The tumor capsule and the root were carefully dissected away. The tumor was removed while preserving the capsule by dissecting the plane between the inner wall of the capsule and the tumor. The single stage posterior approach for presacral giant schwannoma is feasible, and it can be a good surgical alternative to prevent pelvic organ or vascular damage and anterior approach related dystocia and infertility.

Abdominal schwannomas: review of imaging findings and pathology

Schwannomas are typically slow growing, encapsulated benign neoplasms. Visceral schwannomas are rare, and preoperative diagnosis is challenging, as they are often confused with other neoplasms even with advanced imaging studies. Surgical excision is usually needed to establish a definitive diagnosis, as pathology is the "gold standard." We review the imaging findings of abdominal schwannomas focusing on pancreatic, gastrointestinal, and retroperitoneal/adrenal schwannomas with pathology correlation. We conclude that schwannoma should be included in the broad differential diagnosis of an abdominal mass and that when it is unnecessary radical resection can be avoided.

Detection and management of retroperitoneal cystic lesions: A case report and review of the literature

The identification of cystic lesions within the retroperitoneal space is a rare event that poses clinicians the challenge of a difficult diagnosis and disease management. Retroperitoneal cystic lesions account for a group of lesions that range from common benign lesions (e.g., lymphoceles developing as a surgical complication) to rare aggressive malignant neoplasms. Currently, in the majority of cases, image-guided procedures allow for a pathological diagnosis to be achieved in these challenging lesions, thus offering the chance of an appropriate treatment; however, the overall clinical assessment of retroperitoneal cysts is highly demanding. The present study reports the management of a representative clinical case, presenting with a voluminous cystic mass able to dislocate cave vein, whose diagnosis was preceded by a deep vein thrombosis. Computed tomography-scan and ultrasound guided percutaneous drainage were performed to achieve the diagnosis. Following the discussion of the current case report, a review of the pathological and radiological characteristics of retroperitoneal cystic lesions is presented.

A case of pancreatic schwannoma showing increased FDG uptake on PET/CT

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Pancreatic schwannoma is rare and preoperative diagnosis is difficult due to the lack of specific symptoms, radiological characteristics and tumor markers.

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Incidental detection of pancreatic schwannoma is predicted to increase due to the widespread use of CT and MRI. It is important to take into account this tumor in the differential diagnosis of pancreatic tumors.

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We should be aware that FDG-PET/CT shows abnormal accumulation in a benign pancreatic schwannoma.

Introduction

Schwannomas are neoplasms originating from Schwann cells in nerve sheath, but pancreatic schwannomas are rare.

Presentation of case

A 59-year-old female incidentally pointed out a 2-cm-sized solid mass in the pancreas head by computed tomography (CT) which was performed for other reasons. Magnetic resonance imaging (MRI) showed a mass with hypointensity on T1-weighted images and a heterogenous hyperintensity on T2-weighted images. Magnetic resonance cholangiopancreatography (MRCP) showed no abnormal findings in the main pancreatic duct. The mass of the pancreas head showed a significantly increased uptake on fluorin-18 fluorodeoxyglucose positron emission tomography CT (FDG-PET/CT). Based on the radiological findings, a malignant potential tumor was preliminarily considered. Subtotal stomach-preserving pancreatoduodenectomy (SSSPD) was performed to make a definite diagnosis. The resected specimen showed a well-encapsulated circumscribed mass, measuring 2.0 cm, in the pancreas head. Histopathological examination revealed proliferation of spindle cells showing interlacing and palisading patterns in the tumor. The proliferating cells showed no atypia and few mitoses. Immunohistochemically, the spindle cells were positive for S-100 protein. The Ki67 labeling index was approximately 2%. Based on these findings, a diagnosis of benign schwannoma of the pancreas was made.

Conclusion

Although pancreatic schwannoma is a rare neoplasm, it is important to take into account this tumor in the differential diagnosis of pancreatic tumors. In addition, we should be aware that FDG-PET/CT shows abnormal accumulation in a benign pancreatic schwannoma.

Schwannoma of the psoas: An unusual cause of abdominal pain

Schwannomas are usually benign tumours arising from Schwann cells of peripheral nerve sheath. Retroperitoneal location is extremely rare compromising 0.5-5% of all schwannomas, except in patients having von Recklinghausen's disease, in whom retroperitoneal location is more frequent and malignant cases are known to occur. Complete surgical excision with negative margins is the definitive treatment on which the diagnosis is usually made due to nonspecific radiologic appearance. In this article we would like to present an unusual cause of recurrent, abdominal pain in an eighty-six-year-old male.

Contrast MRI Findings for Spinal Schwannoma as Predictors of Tumor Proliferation and Motor Status

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

The goal of this study was to examine the relationship of the proliferation potency based on the MIB-1 index and motor status with features of T2-weighted images (T2WI) and contrast T1-weighted images (T1WI) of spinal schwannoma.

SUMMARY OF BACKGROUND DATA

Spinal schwannomas account for 55% of spinal tumors, but the relationship of cellular proliferation with MRI findings for spinal schwannoma is unknown.

METHODS

The subjects were 48 patients (22 males and 26 females) with spinal schwannoma who were classified into three subgroups: iso/homo, high/rim, and hetero/hetero, based on T2WI/contrast T1WI. A retrospective analysis of tumor size and MIB-1 index was performed in the context of these MRI findings. Intraoperative findings and pre- and postoperative motor performance were also examined.

RESULTS

The average tumor size was 32.4 mm (range 10-130 mm) and the average MIB-1 index was 3.8% (range 1-12). In the three subgroups, there were no significant differences in sex, age, duration of disease, tumor lesion, and dumbbell type. In the hetero/hetero group, the tumor size was significantly greater and the MIB-1 index was significantly higher (both P < 0.05), than the other two groups. The tumor adherence rate was significantly higher for hetero tumors (P < 0.05) and preoperative paralysis was more common in cases with tumor adhesion. The rate of paralysis improvement at 1 month was significantly lower for hetero tumors, but all cases had improved at 6 months.

CONCLUSION

Contrast T1WI MRI was useful for prediction of the proliferative activity and growth of spinal schwannomas, which are associated with increased tumor size and adhesion. A heterogeneous pattern on contrast T1WI indicated an increase in size and adhesion of the tumor. This pattern reflected the preoperative motor status and postoperative motor recovery.

LEVEL OF EVIDENCE

4.

Diffusion-weighted imaging in extracranial head and neck schwannomas: A distinctive appearance

PURPOSE

To evaluate the diffusion weighted (DW) magnetic resonance imaging (MRI) features of the extracranial schwannomas of head and neck.

MATERIALS AND METHODS

The MRI (including DWI) of 12 patients with pathologically proven head and neck schwannomas (4 men, 8 women, with mean age of 32.6 years; age range 16-50 years) were retrospectively evaluated. Images were analyzed for signal intensity and morphology on conventional sequences followed by the qualitative evaluation of DW images (DWI) and measurement of apparent diffusion coefficient (ADC) values.

RESULTS

Majority of the tumors were located in the parapharyngeal space (8/12). All but one showed heterogeneous appearance, with 10 tumors showing scattered areas of hemorrhage. Eight out of 12 tumors showed intensely hyperintense core surrounded by intermediate signal intensity peripheral rim (reverse target sign) on T2-weighted (T2W) images. On DWI, these eight tumors showed a distinctive appearance, resembling target sign on trace DWI and reverse target on ADC map. Out of the remaining four tumors, one showed uniformly restricted diffusion whereas three showed free diffusion. Mean ADC value in the central area of free diffusion was 2.277 × 10(-3) mm(2)/s (range of 1.790 × 10 -(3) to 2.605 × 10(-3) mm(2)/s) whereas in the peripheral area was 1.117 × 10(-3) mm(2)/s (range of 0.656 × 10(-3) to 1.701 × 10(-3) mm(2)/s). Rest of the schwannomas showing free diffusion had a mean ADC value of 1.971 × 10(-3) mm(2)/s.

CONCLUSION

Majority of the head and neck schwannomas showed a characteristic appearance of free diffusion in the centre and restricted diffusion in the periphery of the mass.

RETROPERITONEAL SCHWANNOMA (CLINICAL CASE)

Schwannoma - a tumor growing from Schwann cells of the peripheral nerve sheath. Retroperitoneal schwannoma is a rare tumor accounting for approximately 1 to 5% of all retroperitoneal neoplasms. Retroperitoneal localization occurs for a total in 0.75-2.6% of cases, often they localize in the extremi- ties, the head and neck. Despite the significant progress made currently in the field of instrumental studies for non-organ retroperitoneal tumors, diagnosis and differential diagnosis remain a complex problem requiring further study. Presented clinical case illustrates difficulties in the diagnosis of retro- peritoneal schwannoma. Precise preoperative determination of the tumor relationship with all the nearby organs and vessels according to the different methods of ray diagnostics gives an opportunity to define the tactics of treatment.

Perineal schwannoma

Background

Schwannoma is a benign tumor arising from Schwann cells of the peripheral nerve sheath. Perineal schwannomas are exceptional, and rarely reported in the literature. We report a case of a perineal schwannoma, close to the anal sphincter, and provide a short summary of clinical, radiological and surgical features of this rare entity.

Case presentation

A 62 year-old male patient was admitted for a suspected perineal mass. At clinical examination, he had a soft mass, located on the right of the anus. Computed tomography showed a perineal mass, located on the right side of the anal sphincter that enhanced after injection of the contrast medium. Complete surgical excision of the tumor was performed. The most challenging part during the surgery was the dissection and preservation of the anal sphincter to avoid anal incontinence. Pathologic examination revealed a completely excised schwannoma.

Conclusions

Perineal schwannomas are very rare tumors that are usually asymptomatic, and which present as large masses. Complete excision is necessary to avoid recurrences. Surgical resection may be difficult depending of proximity to the anal sphincter. A cautious dissection in such cases is required in order to reduce the risk of incontinence.

[Retroperitoneal tumors]

BACKGROUND

Retroperitoneal tumors are rare malignancies. The retroperitoneum can host a wide spectrum of pathologies including primary or metastatic lesions.

OBJECTIVE

Treatment of retroperitoneal tumors is often associated with several challenges because of their relative late presentation and anatomic location.

MATERIALS AND METHODS

Because of various pathologies, a detailed case history, laboratory investigation and ultrasound should be performed. Radiologic examinations remain a major component in the diagnosis. In addition to computed tomography, magnetic resonance imaging and positron emission tomography are used. Although radiologic findings are often unspecific, there are often typical findings such as dissemination, margins, vascularization and tumor texture which contribute to the differential diagnosis even before making a definitive diagnosis. Due to the complexity of primary retroperitoneal tumors, which require different treatments depending on the final diagnosis, the treatment approach should be determined in a multidisciplinary tumor conference prior to histological confirmation and initiation of treatment.

CONCLUSION

To ensure the best potential curative treatment modality for retroperitoneal tumors, treatment is best performed in high-volume centers by a multidisciplinary team.

Lateral access to paravertebral tumors

Traditional transabdominal and retroperitoneal approaches for paravertebral tumors can be associated with injury to the viscera and lumbar plexus. The authors provide a technical description of a known approach with a new application for the resection of paraspinal tumors using both open and minimally invasive transpsoas techniques and report on 2 illustrative cases. In both cases, gross-total resection of the tumor was achieved and the patients experienced resolution of their presenting neurological symptoms, although one of the patients required 2 extra days of hospitalization due to an asymptomatic retroperitoneal hematoma, which was conservatively managed.

The authors conclude that the lateral transpsoas approach is a safe approach for paravertebral tumors and may not require an access surgeon.

Primary retroperitoneal masses: what is the differential diagnosis?

Primary retroperitoneal masses include a diverse, and often rare, group of neoplastic and non-neoplastic entities that arise within the retroperitoneum but do not originate from any retroperitoneal organ. Their overlapping appearances on cross-sectional imaging may pose a diagnostic challenge to the radiologist; familiarity with characteristic imaging features, together with relevant clinical information, helps to narrow the differential diagnosis. In this article, a systematic approach to identifying and classifying primary retroperitoneal masses is described. The normal anatomy of the retroperitoneum is reviewed with an emphasis on fascial planes, retroperitoneal compartments, and their contents using cross-sectional imaging. Specific radiologic signs to accurately identify an intra-abdominal mass as primary retroperitoneal are presented, first by confirming the location as retroperitoneal and secondly by excluding an organ of origin. A differential diagnosis based on a predominantly solid or cystic appearance, including neoplastic and non-neoplastic entities, is elaborated. Finally, key diagnostic clues based on characteristic imaging findings are described, which help to narrow the differential diagnosis. This article provides a comprehensive overview of the cross-sectional imaging features of primary retroperitoneal masses, including normal retroperitoneal anatomy, radiologic signs of retroperitoneal masses and the differential diagnosis of solid and cystic, neoplastic and non-neoplastic retroperitoneal masses, with a view to assist the radiologist in narrowing the differential diagnosis.

Retroperitoneal Gastrointestinal Type Schwannoma Presenting as a Renal Mass

Retroperitoneal schwannomas are extremely rare, and unreported in Urology. Often thought to be malignant from imaging the diagnosis is often delayed until Histology. We report a case of retroperitoneal schwanoma thought to be a malignant renal mass. Seventy three year old lady presented with abdominal pain. Imaging showed a mass attached to the renal pelvis thus she underwent a radical nephrectomy. Histology reported retroperitoneal schwannoma. Malignant forms are rare however treatment for these is surgical excision. Awareness of the existence of these tumors may help in avoiding unnecessary radical surgeries by opting for biopsy preoperatively.

A minimally invasive pericoccygeal approach to resection of a large presacral schwannoma: case report

Resection of large presacral schwannomas can present a challenge. The posterior approach is commonly associated with coccygeal disarticulation, partial sacral resection, and muscular disarticulation, which can all result in significant morbidity. Minimally invasive surgery may obviate some of the morbidity traditionally associated with this approach. The authors present the case of a morbidly obese 49-year-old man with an enlarging presacral schwannoma. The patient refused laparoscopic resection because of the morbidity he had experienced with a previous laparoscopic surgery. The tumor was resected using a minimally invasive paracoccygeal approach, which affords improved access with minimal morbidity.

Management of patients with retroperitoneal tumors and a review of the literature

Background

Retroperitoneal tumors (RTs) develop insidiously and are generally seen as large masses, and 50% of RTs are larger than 20 cm at the time of diagnosis. In this article, we share our experience of 5 years of surgical management of RTs.

Methods

We evaluated 28 RT cases operated on in three education hospitals in Turkey from January 2008 onwards, with regard to patients’ demographic characteristics, complaints, weight loss figures, the location and size of the tumor, blood transfusion, intra-operational time, metastases (in malignant cases), additional organ resection, histological grade, local recurrences, average life expectancy, and post-operative treatment methods.

Results

The mean age of the patients was 49 years (range, 18 to 78 years). Twenty (71.43%) were female, and 8 (28.57%) were male. The primary complaint was abdominal pain in 18 patients (64.28%). CT scans were performed in 17 (61%) patients, 10 (35.4%) underwent abdominal MR imaging, and 1 (3.6%) underwent both abdominal CT and abdominal MR imaging. A mass was palpated in the pelvis (suprapubic region) in seven (25%) of the patients during physical examination. The largest tumors were detected in the left lumbar area. The mean tumor size was 12.78 cm (range, 2 to 30 cm). The mean intra-operational time was 192 min (range, 70 to 380 min). The mean hospitalization period was 11 days (range, 8 to 23 days). Seven (25%) patients were reported to have benign tumors, while 21 (75%) were reported to have malignant tumors. The most frequently seen malignant pathology was liposarcoma (eight cases; 38.09%) followed by leiomyosarcoma (five cases; 23.8%) and malignant fibrous histiocytoma (four cases; 19.04%). The earliest local recurrence was detected in the 12th month and the latest in the 28th month. A total of 11 (52.3%) of the total of 21 malignant cases experienced local recurrence within 3 years. The 3-year average life expectancy was 85.7% in the 18 malignant cases.

Conclusions

Due to the low response rate of all but two types of RT to chemotherapy, the best remaining treatment option is surgery with wide resection margins, whereby all macroscopic traces of tumor are removed.

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.

Treatment of large thoracic and lumbar paraspinal schwannoma

BACKGROUND

Paraspinal neurogenic tumors usually expand into the mediastinum and retroperitoneum and can reach a considerable size before they become symptomatic. Such large tumors are rare. We describe 14 cases of large schwannomas (>2.5 cm ø) with mild and late onset of symptoms, which were treated with total surgical resection through a single-approach surgery.

METHODS

In 2013 14 patients with paraspinal large schwannomas were treated in our institutions. Data were analyzed retrospectively. Magnetic resonance imaging (MRI) showed lesions suspicious for a paraspinal schwannoma with partial intraforaminal growth. In case of ambiguity regarding tumor dignity, a needle biopsy was performed before final treatment. Three different approaches and their indications were discussed.

RESULTS

Fourteen patients (7 female and 7 male, ages 18-58 years, mean: 39.8 years) requiring surgical exploration because of a thoracic (6) or lumbar/lumbosacral (8) lesion were treated in our institutions. Two patients received CT-guided needle biopsy preoperatively. Complete resection of the schwannoma was possible through a mini-thoracotomy in 1 case (7 %), a retroperitoneal approach in 2 cases (14 %), and dorsal interlaminar and intercostal fenestration in 11 cases (79 %). Histological examination revealed the diagnosis of schwannoma (WHO grade I) in all cases except one with neurofibroma (WHO grade I). There were no major complications in any case.

CONCLUSION

Large benign schwannomas are rare. They need a tailored treatment, which in most cases works through one surgical approach. Usually it is possible to perform a complete resection with a good postoperative prognosis.