Retroperitoneal Schwannoma:Incidental finding on sonography

Retroperitoneal Schwannoma:Incidental finding on sonography

Retroperitoneal Schwannoma: Incidental findings on Sonography

















Bui, T. D., Nguyen, T. T., Abadir, J., & Hsiang, D. J. (2005). SCHWANNOMA: A RARE PANCREATIC NEOPLASM. Journal of Investigative Medicine, 53(1) doi:

This articles provides overview of pancreatic schwannomas by highlighting that it majorly affects the adult population. Properties of these tumors are given, for example, they vary in size, two thirds of them are cystic and they grossly mimic cystadenomas and cystadenocarcinomas of the pancreas. Magnetic resonance imaging and computed tomography have been highlighted as the primary imaging modalities.

This article indicates what schwannomas are characterized of one being a strong immunoperoxidase staining with S-100 protein marker. The study concludes, as with others studies reviewed herein, that surgical resection of pancreatic schwannomas is curative and that the role played by chemoradiation in management of schwannomas is unclear. This article is important in enlightening the intended audience about schwannomas and that chemoradiation is insignificant in its management.

Cury, J., Coelho, R., Srougi, M. (2007).  Retroperitoneal schwannomas: Case series and literature review.  Clinics, 62 (3), pp. 359-362.

Cury and Srougi in the introduction part highlight that masses rarely occur in the retroperitoneum in the absence of Recklinghausen’s disease. The authors asserts that there have been reports of masses involvement in the penis, testis, tunica vaginalis and spermatic cord. Three experienced cases are presented in the article.

The symptoms for schwannoma are vague and nonspecific. They include dull ache and vague abdominal pain. However, the study explains that unreliable diagnosis are not guaranteed with the use of CT guided core biopsy and fine needle aspiration when it comes to diagnosis of retroperitoneal schwannoma. It is also not recommended to use CT guided biopsy because in many cases there are risks of hemorrhage, tumor seeding and infection. As such, just like other reviewed studies herein, the study recommends complete excision as the best method of managing retroperitoneal sheath tumors. This study is of essence in my study as it will help in reviewing of literature pertaining to different diagnostic tools and also help clinicians understand best options in managing schwannomas.

Damodaran, S., Mahimairaj, G., & Velaichamy, K. (2015). A case series of two cases of juxta-adrenal schwannoma presenting as adrenal mass lesion and review of the literature. Urology Annals, 7(2), 254-258. doi:

In this article, the authors report two cases of juxta‑adrenal schwannomas presenting as symptomatic adrenal mass lesions with both cases being treated by surgical excision. The correct diagnosis was established through histopathological examination. The article also document unique imaging characteristics which assist in preoperative diagnostic of these lesions that are rare.

Their study found out that schwannomas had no sexual or racial predilection and that immunohistochemistry (IHC) is a useful technique to use in detecting Schwan cells tumors since they stain positive for S-100 antigen, laminin and antigen IV.

This article is important for this study as it identifies a unique characteristic of symptomatic mass lesions which can be of essence in diagnosis of Schwan cells and thus, useful to the intended audience who are medicine practitioners and mostly who conduct surgery.

Freitas, V., Saliba, M., de Moraes, E., de Morais Teixeira, G., & de Oliveira, J. (2009). Malignant Schwannoma in patients with von Recklinghausen disease: report of two cases. Brazilian Journal Of Otorhinolaryngology75(1), 160.

This study proposes the use of MRI, CT, Bone Scintigraphy and Angiography in investigating malignancy. Their investigation on three patients did not link the cases of malignant to tobacco but was associated with Recklinghausen’s disease and were aged between 37 and 40. In the final comments the authors advice frequent follow ups since there could be possibility of patients developing metastatic disease.

This article is useful in reference as it is appropriate for the audience and it gives direcives that would be of importance for those in the medicine field.

Fu, H., Lu, B. (2015).  Giant retroperitoneal schwannoma: a case report.  International Journal of Clinical and Experimental Medicine, 8 (7), pp. 11598-11601.

This article evince the difficulty in diagnosing retroperitoneal schwannomas and that imagelogical though has some values, it lacks specificity. In the case in this article, CT scan and B-ultrasound proved difficult to diagnose the mass. Additionally, the study suggests surgical excision for its treatment. The reason for the choice is that schwannomas are not sensitive to radiotherapy and chemotherapy and malgnance could not be excluded by imaging or frozen section. Like other studies, this study recommends follow up. This article is important for my study in understanding the schwannomas in depth.


Goh, B. K. P., Tan, Y., Chung, Y. A., Chow, P. K. H., Ooi, L. L. P. J., & Wong, W. (2006). Retroperitoneal schwannoma. The American Journal of Surgery, 192(1), 14-8. doi:

The article presents surgical experience with 7 retroperitoneal schwannomas patients. The study agrees that retroperitoneal schwannomas are difficult to diagnose as they are usually asymptomatic and are believed to grow slowly. As such, they grow into large sizes without realization since retroperitoneal is flexible and may exhibit cystic degeneration.

The study further states that use of CT scan is unreliable in diagnosing retroperitoneal schwannomas, a view supported by other scientist in this bibliography. Additionally, these authors highlight complete excision as the best method in treatment of retroperitoneal schwannomas. This stance is also seen with Cury and Srougi study. As with some other references reviewed herein, this study is of significance in understanding the nature of schwannomas.


Hamada, K., Ueda, T., Higuchi, I., Inoue, A., Tamai, N., Myoi, A., . . . Hatazawa, J. (2005). Peripheral nerve schwannoma: Two cases exhibiting increased FDG uptake in early and delayed PET imaging. Skeletal Radiology, 34(1), 52-7. doi:

This study presents an investigation by medicine practitioners on involving diagnostic modality that is used in in detection of tumor. Whereas others studies as highlighted here advance use of MRI, CT scans among others, this article presents use of fluoro-D-glucose (FDG)and positron emission tomography (PET) used in detecting tumors.

The study documents FDG-PET scans on patients with suspected musculoskeletal tumors that was done for preoperative staging. It documents two benign schwannomas that increased acitivity on PET scanning at one and two hours after the injection of FDG was done. This finding mimicked another finding that was observed with malignant soft tissue tumors. The study provides a basis for clarification of the role of FDG-PET in distinguishing malignancy from benign tumors.


Hirose, T., Ishizawa, K., Sakaki, M., & Fujii, Y. (2012). Retroperitoneal schwannoma is characterized by a high incidence of cellular type and GFAP-immunoreactivity. Pathology International62(7), 456-462.

This article presents a study on 27 patients aged between 31 and 79, a mean of 57.4. it aimed at clarifying the clinicopathologic characteristics of retroperitoneal schwannomas. The results suggested that retroperitoneal schwannoma occurs more often on middle-aged women, growing to a large size. In half of the cases the study exhibited cellular microscopic features which many of which arise from the GFAP-positive Schwann cell. As such the study records that the presence of hyalinized vessels and dense infiltration of foamy microphages are vital for the differential diagnosis from other spindle cell tumors thus providing a significant information to this study.


Hughes, M., Thomas, J., Fisher, C., Moskovic, E. (2005).  Imaging features of retroperitoneal   and pelvic schwannomas.  Clinical Radiology, 60 (8), pp. 886-893.

The aim of this study was to describe the imaging features of retroperitoneal and pelvic schwannomas. The study found out that schwannomas specifically form large, well-circumscribed masses in the retroperitoneum and most often undergo cystic degeneration.

The study also found out that the mass do not invade or obstruct adjacent structures. This study is important in understanding the nature of retroperitoneal and pelvic schwannomas to avoid confusions. It is thus helpful to surgeons too.



Lopes, C., Zereu, M., Furian, R., Furian, B., & Remonti, T. (2014). Retroperitoneal schwannoma diagnosed by endoscopic ultrasound-guided fine-needle aspiration. Endoscopy46(S 01), E287-E288.

This study looked at a case of a woman who at 59 had epigastric pain and upon conducting a CT scan it was revealed to be a heterogeneous low-attenuation tumor. Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) was subsequently conducted. The study thus document EUS-FNA of retroperitoneal to be a valuable method for preoperative diagnosis of schwannomas and surgery is the best treatment for schwannomas.



Miettinen, M., Sobin, L. H., & Sarlomo-Rikala, M. (2000). Immunohistochemical spectrum of GISTs at different sites and their differential diagnosis with a reference to CD117 (KIT). Modern Pathology,13(10),1134-42. doi:

The study analyzed 500 GI mesenchymal tumors in order to investigate the immunihistochemical markers in the diagnosis and differential diagnosis of GISTs which include intestines, stomach, omentum and mesentry tumors.

The study aimed at clinicians was intended to highlight immunohistochemical spectrum of GIST and point out immunoreactivity patterns in tumors. These, as the article documents have to be considered for differential diagnosis and as such helps in precisely identifying GISTs ultimately avoiding diagnostic pitfall.

Narasimha, A., Harendra Kumar, M., Kalyani, R., & Madan, M. (2010). Retroperitoneal cystic schwannoma:  A case report with review of literature. Journal of Cytology, 27(4), 136-139. doi:

Authors of this article have background in medicine and thus present a report with review of literature documenting retroperitoneal schwannomas and its diagnosis. The introduction part touches on the predominant gender which benign schwannomas occurs and the period in their life it is likely to occur. Additionally, it asserts that it is difficult to diagnose by use of MRI, CT or ultrasonography. Resultantly, the authors assert that medics widely use Fine Needle Aspiration Cytology of retroperitoneal mass lesions in diagnosis.

The article presents a case of a man 60 years of age who complained of abdominal pain since the age of 6 years and mass per abdomen from the age of 40. Due to the weaknesses of the imaging tools, FNAC was is found to be the most important and helpful diagnostic tool for diagnosis of retroperitoneal lessions appropriately. The article also highlights precautions that should be taken such as careful monitoring while conducting surgical resection.

This article is of essence to this study as it indicates how far imaging diagnostic tools can be of help and the alternative diagnostic tool that can carry out the procedure successfully resulting to desired results.


Nirhale, D. S., Parasnis, A., Bora, C., Gupta, R., & Aulakh, P. (2013). Retroperitoneal peripheral nerve sheath tumour of triton type–A case report. Indian Journal of Surgery, 75, 12-14. doi:

This article present a case of malignant peripheral nerve sheath tumor that is not associated with neurofibromatosis type 1 and which arises in the retroperitoneum. The introduction part gives background information on malignant peripheral nerve sheath tumor in relation to malignant triton tumor and the conclusion presents this case as the fourth one to be reported on MTT development in the retroperitoneum not linked to history of NF-1. The research however does not touch on tools most appropriate for diagnosing schwannomas.


Ratnagiri, R., & Mallikarjun, S. (2014). Retroperitoneal ancient schwannoma: Two cases and review of literature. Journal of Cancer Research and Therapeutics, 10(2), 368-70. doi:

The authors of this article begin by providing brief background information on schwannoma and the associated characteristics. In addition, the article indicates that these tumors may have nuclear atypia which may be mistaken for malignant change.

Two cases of retroperitoneal ancient schwannomas which happened to be treated at their institution are discussed. The patients were scanned using CT scan which the process revealed a cystic tumor. The tumors were resected and after 2 years for the first patient 15 months for the second patient, they remain free of disease.

The article is important for this study as it evidences that CT scan and surgical resections can completely eliminate the tumors without recurrences.

Schindler, O. S., Dixon, J. H., & Case, P. (2002). Retroperitoneal giant schwannomas: Report on two cases and review of the literature. Journal of Orthopaedic Surgery, 10(1), 77-84. Retrieved from

This review by an orthopedic surgeon, geriatric medicine specialist and urologist respectively presents the preferred method of surgery in eliminating retroperitoneal schwannomas. The introduction part contains information pertaining benign schwannomas; its origin, victims, its size in terms of diameter among others. Additionally, the article presents challenges clinicians face in diagnosis of retroperitoneal schwannomas in that signs only appear when the tumor grows to a size that is capable of causing compression of intra-abdominal/intra-pelvic organs. Through presentation of two cases of large expanding retroperitoneal schwannomas, the article highlights problems arising from surgical removal of tumor and the possible hazards.

Even though MRI is commonly used as an imaging modality while demonstrating tissue heterogeneity and anatomic location of the tumor, it does not present sufficient information useful in excluding malignancy. As such, needle biopsy is recommended for use by surgeons. This study is useful in evaluating cases presented and the shortcomings evinced by the imaging modalities in use alongside adducing information on needle biopsy in line with sufficient evidence on benign tumor’s nature.

Zhang, S., Wu, S., Yao, K., Dong, P., Li, Y., & Zhang, Z. et al. (2013). Retroperitoneal schwannoma mimicking metastatic seminoma: case report and literature review. Chinese Journal Of Cancer,32(3), 149-152.

This article emphasizes awareness of retroperitoneal schwannoma and its distinction from metastatic seminoma in order to avoid a scenario whereby misdiagnosis is made thus resulting to wrong treatment. The articles mainly targets the audience of clinicians.

The article presents a case in which a patient was administered with etoposide, 3 cycles of cisplatin and bleomycin. It was revealed after a CT scan that there was persistence of the retroperitoneal mass. Consequently, retroperitoneal lymph node dissection was done. After examination the pathologist revealed retroperitoneal schwannoma confirmed by immunohistochemistry. This study gains its relevance in my study as it clearly postulates that no tool of diagnosis should be used singly in diagnosis as this could lead to mistreatment.

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