Schwannoma of the Adrenal Gland

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.

Adrenal schwannoma: why should endocrinologists be aware of this uncommon tumour?

PURPOSE

Adrenal schwannomas (AS) are rare tumours arising from Schwann cells. Due to the high prevalence of adrenal incidentalomas, running into very rare adrenal tumours has become a possibility for high volume expert centres. So far, the clinical behaviour and the radiological characteristics of AS make the pre-operative diagnosis of AS extremely challenging. Due to limited information available, we wanted to summarise the main features of this tumours, in order to raise the profile of an uncommon disease.

METHODS

We performed a MEDLINE and EMBASE research to review the literature. We found 57 case reports and case series and a total of 169 cases, including 2 more cases found in our Institutions. We collected data regarding year of publication, sex, age, and, when available, clinical presentation, hormonal data, radiological features, tumour site and size, treatment, histology and follow-up.

RESULTS

We analysed and discussed the clinical, radiological and pathological characteristics of cases identified, underlying the critical aspects of assessment and management of these tumours which still remain questioned, as, currently, pathologic examination is the only way to make the diagnosis.

CONCLUSIONS

The pre-operative diagnosis of AS is more than challenging and pathologic examination is so far the only way to make a certain diagnosis. Therefore, it is important to consider also the AS in the list of possible diagnoses when faced with a large not secreting adrenal tumour, with suspicious radiological features.

Continuous and progressive 'wash-in' without 'wash-out' of contrast in adrenal mass: a useful feature of ganglioneuroma

Computed tomography (CT) scan is a useful and widely performed diagnostic modality to evaluate adrenal masses. Nature of the mass determines the degree of attenuation both in unenhanced and in different phases of contrast enhancement. Benign neurogenic tumours like ganglioneuroma mimicks pheochromocytoma and adrenocortical carcinoma in non-contrast CT scan. The 'adrenal protocol' routinely calculates the wash-out pattern at delayed venous phase (DVP) (15 min) following contrast administration to differentiate majority of benign masses from the malignant ones. Ganglioneuromas typically exhibit continuous wash-in of contrast where enhancement gradually increases to attain its peak in DVP. Such wash-in pattern is different from the wash-out pattern observed in pheochromocytomas or adrenocortical adenomas or carcinomas. Presence of this wash-in pattern provides a useful clue to the clinician for underlying ganglioneuroma in hormonally inactive adrenal masses with suspicious morphological appearances. This wash-in pattern also effectively rules out any malignant potential of ganglioneuroma, and thus helps in preoperative decision-making.

Clinical features and outcomes of adrenal schwannoma: a study of 13 cases from a single centre

BACKGROUND

Adrenal schwannomas (AS) are extremely rare neoplasms. This study shares our experience regarding the diagnosis and operative management of AS.

METHODS

Clinical details, radiologic, laboratory, and pathologic findings as well as follow-up data were analysed retrospectively for 13 AS patients who accepted surgery at a tertiary referral hospital in China between 1 January 1996, and 31 December 2017.

RESULTS

The mean age of the patients at diagnosis was 44.7 ± 13.7 years (range 19-62 years; male: female ratio, 1:1.16), of whom seven patients had unilateral AS on the right side, and the remaining six on the left side. None of the cases were hormonally active. None of the 13 cases were diagnosed as AS by CT imaging before the operation. Among the patients, ten were asymptomatic. The mean preoperative size was 7.1 ± 3.2 cm (range 1.6-12.6 cm). All patients underwent surgery, with open adrenalectomy in five patients and laparoscopy in eight patients. The mean tumor size on pathologic examination was 6.8 ± 3.0 cm (range 3.0-11.7 cm). The surgical specimens were confirmed by pathological examination. During a median follow-up of 60.8 ± 17.7 months, no patients showed recurrence or metastasis.

CONCLUSION

The preoperative diagnosis of AS remains difficult despite the advances in imaging examinations. After complete resection, the prognosis of AS is excellent.

Benign adrenal and suprarenal retroperitoneal schwannomas can mimic aggressive adrenal malignancies: case report and review of the literature

The suprarenal retroperitoneum and adrenal gland is a rare site of origin for benign schwannomas which frequently present as larger and more aggressive lesions than schwannomas identified elsewhere. These tumors are often surgically excised. We present a case of an 81-year-old asymptomatic man presenting with an incidental 10 cm left suprarenal retroperitoneal mass identified on CT. The mass was indiscernible from the adrenal gland, demonstrating heterogeneous enhancement with a centrally cystic/necrotic core, and punctate calcifications. Subsequent core needle biopsy demonstrated a benign adrenal schwannoma. The lesion has been managed conservatively with imaging follow up and without complication. DISCUSSION: Our review of the literature identifies 121 reported in vivo benign adrenal and suprarenal schwannomas published to date with imaging features available for 90 cases (74%). All cases were encapsulated with the average size measuring over 6.5 cm. Fifteen percent (13/84) of reported lesions measured over 10 cm at presentation. Punctate calcification was present in 50% (26/52) of reporting cases. Nearly 50% (40/86) of cases demonstrate cystic/necrotic appearances on imaging. Despite aggressive appearances, our case demonstrates that biopsy and surveillance may represent a reasonable alternative to surgery in suboptimal surgical candidates.

Adrenal schwannoma in a female patient; A rare benign neoplasm: Case report and literature review

INTRODUCTION

Schwannomas are rare, slow-growing, usually benign tumors that originate from myelin-producing Schwann cells. Adrenal schwannomas are an exceptionally rare subset of these tumors, with few cases reported in the literature.

PRESENTATION OF CASE

We present the case of a 44-year old female patient being evaluated for chronic abdominal pain at the outpatient clinic. Clinical and laboratory workup was unremarkable. An abdominal CT scan was performed, revealing a left suprarenal solid mass (5 × 6 cm). Surgical resection of the adrenal gland was performed, given the patient's symptoms, the size of the tumor, and its malignant potential. The patient completed the postoperative period satisfactorily, and her symptoms improved. Histopathological findings were compatible with a benign adrenal schwannoma.

DISCUSSION

Schwannomas generally appear in the head, neck and extremities, with the vestibulocochlear nerve being the most frequently involved site. Retroperitoneal schwannomas account for 1-5% of retroperitoneal masses and comprise only 1-3% of all schwannomas. Their incidence increases with age, from 4% in the general population, reaching 7% in patients over 70 years of age.

CONCLUSION

Adrenal incidentalomas represent a diagnostic challenge. Because of the malignant potential of large (> 4 cm) adrenal masses and the lack of characteristic findings using conventional imaging techniques and laboratory diagnostic tools, surgical excision with histopathology and immunohistochemistry analysis are required for definitive diagnosis and optimal management.

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.

Adrenal Schwannoma Treated with Open Adrenalectomy: a Case Report

Adrenal schwannomas are very rare tumors accounting for only 0.2% of the adrenal tumors. These are very difficult to diagnose preoperatively and usually present as incidental non-secreting adrenal masses in asymptomatic patients or in patients with non-specific complaints. Computed tomography (CT) and magnetic resonance imaging (MRI) are required to aid the diagnosis, but adrenal schwannomas cannot be distinguishably confirmed on the basis of imaging alone. Histopathological examination (HPE) is essential for accurate diagnosis. We report a rare case of a right adrenal schwannoma in a 68-year-old man. The clinical evaluation was unremarkable and the radiological examination revealed a suprarenal mass lesion on ultrasonography (USG). CT revealed a right adrenal mass which was purported to be likely malignant. Right adrenalectomy was performed by the open approach along with excision of the surrounding enlarged lymph nodes. The postoperative course was uneventful. HPE established the adrenal mass to be a schwannoma, a benign tumor arising from Schwann cells, an exceedingly unusual occurrence in the adrenal glands. A non-secreting adrenal mass can be easily misjudged and the exact diagnosis of the lesion cannot be made sure of without both radiologic and pathologic confirmation. Unilateral adrenal primary or metastatic lesions need pathological confirmation as it can dramatically affect prognosis. Unusual tumors of the adrenal gland like schwannomas may be found incidentally or otherwise and will generate difficulties in establishing the right management. Complete excision is the treatment of choice whenever feasible and will also clarify pathology.

Adrenal Schwannomas: Rare Tumor of the Retroperitoneum

Schwannoma is a benign neurogenic tumor originating from Schwann cells. These produce the myelin sheath that covers peripheral nerves that are often affected. This latter localization is extremely rare, and only a few case reports can be found in the medical literature. Studies have shown that approximately 0.5% to 5% of schwannomas are retroperitoneal, constituting 0.2% of adrenal incidental tumors. These usually present as incidental findings, nonsecreting adrenal masses in asymptomatic patients. Diagnosis of a schwannoma is based on detection of spindle cells with Antoni A and Antoni B regions in histological sections and positive staining for S-100 protein by immunohistochemical analysis. We report a case of an incidentally identified during an abdominal ultrasound examination with schwannoma localized in the left adrenal gland.

A case series of two cases of juxta-adrenal schwannoma presenting as adrenal mass lesion and review of the literature

Schwannomas are rare tumors in the retroperitoneal location. They can pose a diagnostic dilemma when presenting as an adrenal mass lesion due to their imaging characteristics. We report two cases of juxta-adrenal schwannomas presenting as symptomatic adrenal mass lesions. In both the cases, the clinical examination and functional evaluation was unremarkable and the radiological examination revealed a mixed intense adrenal mass lesion in one case with predominantly hyperintense areas and a very hyperintense lesion in another, in T2-weighted images, mimicking a adrenocortical malignancy and a pheochromocytoma respectively. Both cases were treated by surgical excision. Histopathological examination established the correct diagnosis of schwannoma, which was confirmed by immunohistochemical staining. Juxta-adrenal schwannoma is rare tumors of the retroperitoneum, which should also be borne in mind whenever encountering large nonsecreting adrenal tumors. We report a unique imaging characteristic, which helps in preoperative identification these rare lesions.

Adrenal ganglioneuroma: features and outcomes of 27 cases at a referral cancer centre

BACKGROUND

Adrenal ganglioneuroma (AGN) is a rare neurogenic tumour that can mimic other adrenal neoplasms. Limited information, mostly derived from small cases series, is available for AGN.

METHODS

A retrospective review for AGNs seen at a tertiary referral centre describing important features to distinguish AGN from other adrenal neoplasms.

RESULTS

Of 53 ganglioneuromas, 27 were AGNs. Median age was 31 years (range, 1·7-64 years) and median tumour size was 8 cm (range, 1·5-20 cm). Seventeen AGNs (63%) were detected incidentally and nine patients (33%) presented with abdominal/back discomfort. Catecholamine levels, available for 21 patients, were normal. On computed tomography (CT), most AGNs were homogenous and well circumscribed with a median density of 32·5 Hounsfield units (HU) on unenhanced CT; 40 HU on postcontrast venous phase; and 66·5 HU on delayed postcontrast phase. On magnetic resonance imaging (MRI), AGNs had hypo-intense signal on T1-weighted images with heterogeneous hyperintense signal on T2-weighted images. In four patients, there was no tumour growth during median follow-up of 48 months (range, 21-60 months). One patient had malignant peripheral nerve sheath tumour arising from AGN. Thirteen patients with resected AGN had no recurrence during a median follow-up of 50 months (range, 2-135 months).

CONCLUSIONS

We herein describe the largest AGN series reported to date. Isolated AGNs do not produce catecholamines and have CT imaging characteristics that can help in distinguishing them from other adrenal and para-adrenal neoplasms. The natural history of AGNs is usually benign, although local extra-adrenal extension or malignant transformation can rarely occur.

A rare adrenal incidentaloma: adrenal schwannoma

Adrenal schwannoma is an extremely uncommon cause of incidentaloma. It originates from neural sheath Schwann cells of the adrenal gland. We report the case of a left adrenal schwannoma incidentally discovered in a 32-year-old woman during examination of bloated feeling and stomach ache. The patient was incidentally found to have a left adrenal mass of 9 cm on abdominal ultrasonography. Computed tomography (CT) of the abdomen and [¹⁸F] fluorodeoxyglucose positron emission tomography (PET) were also performed. Metabolic evaluation was unremarkable. Due to the large size of the tumor, left adrenalectomy was performed. The postoperative course was uneventful. Histological examination established the diagnosis of schwannoma. This diagnosis was supported by immunohistochemistry of S-100 and vimentin positivity. In conclusion, adrenal schwannoma is an extremely rare entity and can grow considerably in size. The present case report emphasizes that clinicians should be aware of the possibility of retroperitoneal schwannoma. Total excision of benign schwannoma is associated with a favorable outcome. To our knowledge, there are case reports of schwannoma with CT and magnetic resonance imaging findings in the literature, although this is the first schwannoma case with PET-CT imaging.

Adrenal schwannoma: a rare type of adrenal incidentaloma

Adrenal schwannoma is a rare type of adrenal incidentaloma, an adrenal lesion found incidentally, usually on imaging or autopsy. Computed tomography and magnetic resonance imaging are tools used to evaluate adrenal lesions. The diagnosis of adrenal schwannoma, however, cannot be made on imaging alone. Surgical resection is the primary means of management of adrenal schwannomas, as it is not possible to distinguish the schwannoma from malignant entities simply based on imaging. Histopathologic features of adrenal schwannomas are similar to those of schwannomas found at other sites. Conventional schwannomas, consisting of alternating Antoni A and Antoni B areas as well as Verocay bodies, have distinct microscopic features and can be readily distinguished from other entities. Cellular schwannomas, on the other hand, consist only of intersecting fascicles of spindle cells or Antoni A areas, resulting in a wide differential diagnosis. Ancillary studies such as immunohistochemical analysis and electron microscopy can help to provide a specific diagnosis.

Laparoscopic resection of an adrenal schwannoma

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Three uncommon adrenal incidentalomas: a 13-year surgical pathology review

BACKGROUND

The discovery of adrenal incidentalomas due to the widespread use of sophisticated abdominal imaging techniques has resulted in an increasing trend of adrenal gland specimens being received in the pathology laboratory. In this context, we encountered three uncommon adrenal incidentalomas.The aim of this manuscript is to report in detail the three index cases of adrenal incidentalomas in the context of a 13-year retrospective surgical pathology review.

METHODS

The three index cases were investigated and analyzed in detail with relevant review of the English literature as available in PubMed and Medline. A 13-year retrospective computer-based histopathological surgical review was conducted in our laboratory and the results were analyzed in the context of evidence-based literature on adrenal incidentalomas.

RESULTS

A total of 94 adrenal specimens from incidentalomas were identified, accounting for 0.025% of all surgical pathology cases. In all 76.6% were benign and 23.4% were malignant. A total of 53 females (56.4%) and 41 males (43.6%) aged 4 to 85 years were identified. The benign lesions included cortical adenoma (43.1%), pheochromocytoma (29.3%) and inflammation/fibrosis/hemorrhage (8.3%). Metastatic neoplasms were the most common malignant lesions (50%) followed by primary adrenocortical carcinomas (31.8%) and neuroblastoma (13.6%). These cases were discovered as adrenal incidentalomas that led to surgical exploration.The three index cases of adrenal incidentalomas with unusual pathologies were encountered that included (a) adrenal ganglioneuroma, (b) periadrenal schwannoma and (c) primary adrenal pleomorphic leiomyosarcoma. These cases are discussed, with a literature and clinicopathological review.

CONCLUSIONS

Adrenal lesions are uncommon surgical specimens in the pathology laboratory. However, higher detection rates of adrenal incidentalomas aided by the ease of laparoscopic adrenalectomy has resulted in increased adrenal surgical specimens leading to unsuspected diagnostic and management dilemmas. Accurate pathological identification of common and uncommon adrenal incidentalomas is essential for optimal patient management.

Experience with adrenal schwannoma in a Chinese population of six patients

OBJECTIVES

Benign adrenal schwannoma is an extremely uncommon cause of incidentaloma. This article describes our experience with the diagnosis and treatment of adrenal schwannoma in a Chinese population of 6 patients. To our knowledge, this is the largest series of this uncommon adrenal tumor treated in a single center.

METHODS

From May 1999 to May 2009, 6 patients with incidentally discovered adrenal schwannoma were operated on at a tertiary referral hospital in Eastern China. Clinical details, radiographic features, laboratory examinations, pathological findings, and follow-up data of these patients were analyzed.

RESULTS

Of the 6 patients, 4 were females (F) and 2 were males (M), with a mean age of 40.5 yr (range: 30-47, M:F=2:1). The 6 patients were managed with open unilateral adrenalectomy; 5 patients had schwannomas on the left side, and 1 on right side. Abnormal urine catecholamine was detected in 1 patient. The mean pathological size of these tumors was 4.3 ± 1.1 cm. The diagnosis of schwannoma was based on classic histological findings, and supported by immunohistochemistry of S-100, vimentin, and ABC positivity. In the follow- up of 47.5 ± 32.3 months, no recurrence and metastasis were observed.

CONCLUSIONS

Although there may be some clues for radiological diagnosis of adrenal schwannoma, preoperative misdiagnosis is not infrequent. Those tumors may occasionally have endocrine function. Histological examination is the key of diagnosis, and surgical resection is the treatment of choice once malignancy cannot be excluded by preoperative analyses.

Solitary fibrous tumor of the adrenal gland with unusual immunophenotype: a potential diagnostic problem and a brief review of endocrine organ solitary fibrous tumor

Solitary fibrous tumor was initially thought to be a pleura-based tumor. However, over the last two decades, its involvement in a variety of extrapleural sites gained recognition. Nonetheless, a primary involvement of the endocrine organs is rare, and in this report, we detail an instance where the tumor affected the adrenal gland of a 71-year-old Arab man. On histology, besides the typical morphologic features seen in solitary fibrous tumor, the neoplasm also exhibited unusual features on immunohistochemistry such as positive staining for cytokeratin AE1/3 and calponin in conjunction with diffuse expression for S-100. The genetic tests for t(X:18) as seen in synovial sarcoma were negative, and the overall histological appearance favored a diagnosis of solitary fibrous tumor. To the best of our knowledge, this report represents the fifth case of a solitary fibrous tumor primarily occurring in the adrenal gland. The differential diagnoses of this neoplasm in our case and a brief summary of solitary fibrous tumor primarily involving the various endocrine organs are presented.

Adrenal ganglioneuromas: a 10-year experience in a Chinese population

BACKGROUND

Adrenal ganglioneuroma (GN) is extremely rare. The present study is to describe the largest series of this adrenal tumor treated in a single medical center to our knowledge.

METHODS

Clinical details, radiologic, laboratory, and pathologic findings as well as follow-up data were analyzed retrospectively in 17 patients with incidentally discovered adrenal GN who received operative resection at a tertiary referral hospital in eastern China between June 1999 and June 2009.

RESULTS

The mean age of the 17 GN patients was 39.2 years (range, 7-72; male:female ratio, 1:2.4), of whom 13 patients had unilateral GN on the right side, and the remaining 4 on the left side. None of the 17 tumors was hormonally active. Only 6 of the 17 GN cases were diagnosed as benign nerve cell tumors by computed tomography or magnetic resonance imaging before operation. Treatment consisted of open unilateral adrenalectomy in 9 patients and laparoscopy in 8 patients. The mean pathologic size of the adrenal GNs was 6.3 +/- 3.1 cm (range, 1.0-13.0). Ultrastructural examination provided additional support for confirming the diagnosis.

CONCLUSION

Although there have been some clues for radiologic diagnosis of adrenal GN, pre-operative mis- and maldiagnosis are not infrequent. We recommend that complete operative resection should be considered once malignancy cannot be excluded by pre-operative evaluation. Laparoscopic adrenalectomy is a reasonable option at least for tumors < or =7 cm.

Adrenal incidentalomas: experience from a retrospective study in a Chinese population

BACKGROUND

With no generally accepted criteria for preoperative differential diagnosis between benign and malignant adrenal lesions, management of adrenal incidentalomas, especially those between 4 and 6 cm, remains controversial.

PATIENTS AND METHODS

Clinical details, radiological diagnosis, laboratory examination, intervention measures, and follow-up data were noted in 152 patients with adrenal incidentaloma hospitalized at a tertiary referral hospital in eastern China between July 1999 and February 2008. Pathologic diagnoses were analyzed in surgical cases.

RESULTS

Of 143 surgical patients, the mean pathologic size of the tumors was 5.6 ± 3.2 cm (range 0.5 to 22.0 cm). The final benign pathologic diagnosis mainly included adrenocortical adenoma (31.3%), pheochromocytoma (18.8%), myelolipoma (16.7%), and ganglioneuromas (9.0%). The incidence of malignancy was 6.9%. Based on the size criterion of 6 cm, there was a significant difference between malignant and benign tumor groups (P=0.007), but based on the size criterion of 4 or 5 cm, there was no significant difference between the two groups.

CONCLUSIONS

In our experience, the incidence of malignancy in adrenal incidentalomas was generally low, but relatively high in adrenal incidentalomas >6 cm. Nerve cell tumors constitute a significant number of cases of adrenal incidentaloma. Overtreatment of nonfunctional incidentalomas <4 cm remains frequent in China, and close follow-up for this group is recommended. Factors such as radiologic characteristics and patient concern should be taken into account for nonfunctional incidentalomas between 4 and 6 cm (not including 6 cm), for which laparoscopic adrenalectomy is a reasonable option.

Schwannomas of the left adrenal gland and posterior mediastinum

Schwannoma is a rare tumor of neural crest cell origin. Most schwannomas occur in the head, neck, stomach or limbs, with a few cases occurring in the retroperitoneal space. A 30-year-old Taiwanese woman presented with a 1-week history of left anterior chest discomfort and left flank pain. The laboratory findings and endocrine studies were all within normal limits. Chest X-ray revealed masses in the posterior mediastinum. Chest computed tomography and magnetic resonance imaging showed several masses in the left paraspinal region and in the left adrenal region. The patient underwent total excision of the left paraspinal tumors and laparoscopic left adrenalectomy. Pathologic studies showed a picture of benign schwannoma. In conclusion, preoperative differentiation of benign schwannoma from malignant peripheral nerve sheath tumor or other tumors is important for good prognosis. Total excision of benign schwannoma is associated with favourable outcome in patients.

Intraneural perineurioma: a systematic review with illustrative cases

CONTEXT

Intraneural perineurioma may be confused with other "onion bulb" Schwann cell entities (localized hypertrophic neuropathy, reactive/demyelinating processes, or inherited polyneuropathies of Charcot-Marie-Tooth/Dejerine Sottas) due to similar clinical, radiologic, and histologic features. Perineurial and Schwann cells can only be differentiated by ultrastructure and immunohistochemsitry.

OBJECTIVE

To identify and summarize the clinicopathologic features of true cases of intraneural perineurioma from the English language literature.

DATA SOURCES

A systematic review was performed on definitive intraneural perineuriomas identified through Medline. Baylor College of Medicine-affiliated hospitals' anatomic pathology databases yielded 2 illustrative intraneural perineurioma cases.

STUDY SELECTION

Intraneural perineurioma inclusion criteria consisted of characteristic histology and confirmation of perineurial cell lineage by either immunohistochemistry (epithelial membrane antigen positive, S100 protein negative) and/or ultrastructural analysis (thin cytoplasmic processes with an incomplete basal lamina, poorly formed tight junctions, and pinocytotic vesicles).

DATA EXTRACTION

Clinicopathologic data were extracted from all identified articles, with subsequent statistical analysis of the following parameters: age, sex, race, tumor location, tumor size, duration of symptoms prior to diagnosis, treatment modalities and outcomes measures, follow-up assessment for tumor recurrence and metastasis, clinical features (history of trauma, motor/sensory abnormalities, clinical/family history), and diagnostic workup (routine histology, immunohistochemistry, ultrastructural analysis, and molecular/cytogenetic characteristics).

CONCLUSIONS

Intraneural perineurioma is a neoplastic proliferation of perineurial cells with unique immunohistochemistry and ultrastructural features, and it is distinct from other onion bulb Schwann cell-derived entities. Despite harboring molecular abnormalities of the long arm of chromosome 22, intraneural perineurioma has not been associated with neurofibromatosis. Intraneural perineurioma is a benign peripheral nerve sheath tumor that does not recur or metastasize.

Uncommon adrenal masses: CT and MRI features with histopathologic correlation

Adrenal glands are common sites of diseases. With dramatically increased use of computed tomography (CT) and magnetic resonance (MR) imaging, more and more uncommon adrenal masses have been detected incidentally at abdominal examinations performed for other purposes. In this article, uncommon adrenal masses are classified as cystic masses (endothelial cysts, epithelial cysts, parasitic cysts, and pseudocysts), solid masses (ganglioneuroma, ganglioneuroblastoma, extramedullary plasmacytoma (EMP), neurilemmoma, and lymphoma), fat-containing masses (myelolipoma, teratoma), and infectious masses (tuberculoma), and the imaging features of these uncommon masses are demonstrated. Although most of these lesions do not have specific imaging features, some fat-containing masses and cystic lesions present with characteristic appearances, such as myelolipoma, teratoma, and hydatid. Combination with histopathologic characteristic of these uncommon masses of adrenal gland, radiological features of these lesions on CT and MR imaging can be accurately understood with more confidences. Moreover, CT and MRI are highly accurate in localization of uncommon adrenal masses, and useful to guide surgical treatments.

Adrenal schwannoma: CT and MRI findings

We report a case of adrenal schwannoma, an extremely rare retroperitoneal neoplasm. The patient was a 33-year-old man who presented with an abdominal mass that was discovered at abdominal sonography. Computed tomography showed an 8-cm well-circumscribed homogeneous mass that enhanced slightly after intravenous administration of contrast material. Magnetic resonance imaging showed low signal intensity on T1-weighted images and heterogeneously high signal intensity on T2-weighted images. Although these imaging findings are nonspecific, adrenal schwannomas should be included in the differential diagnosis of solid nonfunctioning adrenal tumors.